Texas Instruments bq25040 User manual

User's GuideSLUU358 – April 2009
1.1-A, Single-Input, Single-Cell, Li-Ion Battery ChargerWith 50-mA LDO and 2.3-A Production Test Support
This user's guide describes the bq25040 evaluation module (EVM), how to setup the EVM to perform astand-alone evaluation or interface with a system or host. The charger is designed to deliver up to 1.1 A ofcontinuous current to the battery output in the adapter mode, ISET, or current limits the input to either 100mA or 500 mA when in USB100/500 modes. The charge is programmed from the factory for 0.51 A inISET mode. In the Protection Test Support (PTS) mode, the battery output is capable of delivering > 2.3 Aof current for short pulses. The LDO regulator output can deliver up to 50 mA of current.
Contents1 Introduction ................................................................................................................... 22 Considerations When Testing the bq25040 IC .......................................................................... 23 Performance Specification Summary ..................................................................................... 24 Test Summary ................................................................................................................ 34.1 Equipment ........................................................................................................... 34.2 Equipment and EVM Setup ........................................................................................ 34.3 Test Procedure ...................................................................................................... 35 Schematics ................................................................................................................... 66 Layout ......................................................................................................................... 77 Bill of Materials ............................................................................................................... 8
List of Figures
1 Evaluation Setup Charging Circuit Shown; Pulse Programming Circuit not Shown ................................ 32 One-Pulse Programming Shows Change From USB500 to ISET Mode ............................................. 43 Two-Pulse Programming Shows Timing of Program Change From 0.4 A to 0.1 A ................................. 54 Power-Up Sequence Shows Timing Between Vin, Viset, Vpg, and Vchg. C1: Chg @ JMP1; C4: PG @JMP8; LEDs Pulled Up to 4.15-V Battery ................................................................................ 55 Basic EVM Charger Circuit ................................................................................................. 66 Circuit for Programming Pulse (Typically Done by Host) ............................................................... 67 Assembly Layer .............................................................................................................. 78 Top Copper Layer ........................................................................................................... 79 Bottom Copper Layer Bottom View ....................................................................................... 8
List of Tables
1 HPA437A Bill of Materials - bq25040 ..................................................................................... 8
SLUU358 – April 2009 1.1-A, Single-Input, Single-Cell, Li-Ion Battery Charger With 50-mA LDO and 2.3-A Production Test Support 1Submit Documentation Feedback

1 Introduction
2 Considerations When Testing the bq25040 IC
3 Performance Specification Summary
Introduction www.ti.com
The bq25040 is an integrated Li-ion linear battery charger targeted at space-limited portable applications.It operates from either a USB port or ac adapter and charges a single-cell, Li-Ion battery with up to 1.1 Aof charge current. The bq25040 has a single-power output that charges the battery. A system load can beplaced in parallel with the battery. The charge current is programmed using the ISET and EN/SET inputs.The charge current is programmable to USB100, USB500, or a user-programmed charge current up to 1.1A. Additionally, a 4.9-V, 3%, 50-mA LDO is integrated into the integrated circuit (IC) for supplyinglow-power external circuitry. The single-input interface (EN/SET) is used to select the charge current andto place the bq25040 into Production Test Mode (PTM). In PTM, the bq25040 operates as a linearregulator without a battery connected, where the output is regulated at 4.2 V and supplies up to 2.3 A tocalibrate GSM transceivers.
The battery is charged in three phases: conditioning, constant current, and constant voltage. In all chargephases, an internal control loop monitors the IC junction temperature and reduces the charge current if aninternal temperature threshold is exceeded.
The charger power stage and charge current sense functions are fully integrated. The charger functionhas accuracy current and voltage regulation loops, charge status display, and charge termination.
The input current is regulated by the ISET loop or may be restricted by the USB current-limit circuitrywhen in either USB100 or USB500 mode.
The input connection to the LDO is connected upstream of the charge-sense circuit and is not part of thecurrent-regulation or current-limit circuit. It is the designer's responsibility to ensure that excessive loadingon the LDO output does not exceed USB specifications. The USB500 mode is set for a 400-mA currentlimit so that the LDO load does not cause the USB500 limit to be exceeded.
The LEDs can be run from any power source and are connected to the LDO from the factory. Moving theresistor from R20 to R21 connects the LEDs to the battery. Note that as the battery voltage decreases, theilluminated LED dims.
JMP6 is a connection to an onboard pulse generator circuit that can program the desired mode via pulses.Use only one shunt on JMP1 through JMP5 to program one through five pulses, respectively. The pulsegenerator always starts or stops in the low state, which leaves the IC in its active state. The part can onlybe programmed once unless it is reset by cycling power or removing JMP6. Removing JMP6 allowsEN/SET to be pulled high and disables the IC. Reapplying the shunt to JMP6 pulls EN/SET low andenables the IC to the USB500 mode. Toggling switch S1 from the UP position to the DOWN position andback UP delivers the program pulse(s) to the IC.
SPECIFICATION TEST CONDITIONS MIN TYP MAX UNITS
Input dc voltage, V
IN
In recommended voltage range 4.75 5 6.5 VReduced performance range, Vin Voltage outside recommended range
(1)
3.5 30 VPower dissipation Pdiss = (V
IN
Vout)
(1)
Iout
(2)
1.5 WI
OUT
R1 = 1k 0.5 0.8 A
(1)
Input voltage range is specified for normal operation. Input voltage between UVLO and 4.75 V has limitations and may havesome functionality, but does not damage the IC nor present any safety issue with the battery. Input voltage above OVP and lessthan 30 Vdc has no operation and will not damage the IC. Lower input voltage (closer to dropout operation) produces less heatdissipation and potentially better performance.(2)
The junction temperature rise above ambient is proportional to the power dissipation. Once the junction temperature reaches~125 °C, thermal regulations reduces the charge current when not in PTS mode.
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4 Test Summary
4.1 Equipment
4.2 Equipment and EVM Setup
4.3 Test Procedure
www.ti.com Test Summary
This section covers the setup and tests performed in evaluating the EVM.
•Power supply +5.1 ±0.1 V, current limit set to 1.5 ±0.1 A•Battery: 4.2 V LiCoO2 or equivalent•LDO Load: from 100- Ωto 10k- Ωresistor•Three Fluke 75 DMMs (equivalent or better)•Oscilloscope, Model TDS220 (equivalent or better)
•Preset P/S#1 to 5.1 ±0.1 V, 1.5 ±0.1-A current limit, turn off and connect to J1 (+ to IN and - to GND).•Connect a fully discharged battery to J2 (+ to BAT+ and - to BAT-).•Apply a 1-k Ωload resistor to J3-1/2.•Apply shunt jumpers to JMP1, JMP6, JMP7, and JMP8.•Set switch, SW1, in the UP position.•Adjust R7 fully CW, and then back off four turns CCW.•Connect the DMMs and oscilloscope as shown in Figure 1 , if desired.
Figure 1. Evaluation Setup Charging Circuit Shown; Pulse Programming Circuit not Shown
1. Make sure setup procedure was followed.2. Turn on P/S#1; preset to 5.1 Vdc.3. Verify that the PG (D1) and CHG (D2) LEDs turned on. Verify that the input/output current is around~0.4 A (DMM3 is ~40 mV). This is the power-up USB500 default mode (no programming pulses havebeen delivered yet) and typically delivers up to ~400 mA. The charge current limit is set lower than 500mA to ensure that the total charge and LDO (maximum of 50 mA) current do not exceed 500 mA onthe input.4. Set the scope to trigger off of CH2 (positive trigger, 1 ms/div), to capture the program pulse going to(EN/SET TP6). Note that only one shunt at a time should be placed on JMP1 through JMP5 to selectthe desired number of programmed pulses.
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Vin
V_EN/SET
Vout
V_0.1 ohm_BAT
Test Summary www.ti.com
5. Switch, S1, DOWN, then back UP. The scope captures one pulse on CH2 (Figure 2 ). The pulse mustbe less than 1.5-ms wide. If too wide, the potentiometer, R7, can adjust the pulse width.6. Verify that the input current changes from 0.4 A to 0.51 A (one pulse programmed the IC for ISETmode). The ISET resistor, 1 k Ω, programs the ISET mode to ~0.51 A. Note that the IC can only beprogrammed once. If a different program level is desired, the part must be reset by cycling power orpulling EN/SET high to disable the IC.7. Remove shunt JMP6, and verify that the input current goes to zero. Removing the shunt, JMP6, allowsEN/SET to be pulled up. This disables the charge and allows programming to be done once EN/SET ispulled back low by replacing the shunt JMP6.8. Replace shunt on JMP6, and move shunt on JMP1 to JMP2 (two-pulse programming). The chargerreturns to the USB500 mode, delivering ~400 mA. If the IC comes up in a different mode, then whileplacing the shunt on JMP6, a contact bounce occurred and the IC was programmed. Remove andreplace the shunt if this happens.9. Switch, S1, DOWN, then UP to program charger to USB100 mode (Figure 3 ).10. This procedure can be repeated (steps 7 to 9) for the shunt on any jumper JMP1 through JMP5 toprogram one to five pulses, respectively. Note that programming three pulses puts the IC in PTS modeand delivers > 2.3 A if the source current is available and the load is great enough. This mode isintended for production testing without a battery. If a less-than-full battery is connected, the currentmay exceed the recommended charge current of the battery or the charger circuit. For maximumcurrent, the duty cycle must be less than 20% and for no longer than 10 ms. See the data sheet forprogramming information (SLUS910 ).11. Verify that the LDO output voltage on DMM#2 measures ~4.9 Vdc, 0.1 V.12. Allow battery to charge to full and verify that D2 LED turns off.13. Discharge battery below 4.1 V, and verify that the charging is enabled and the D2 CHG LED is off forthe second and subsequent charges.14. Figure 4 shows the power up and timing of the Stat pins and charge current.
Figure 2. One-Pulse Programming Shows Change From USB500 to ISET Mode
41.1-A, Single-Input, Single-Cell, Li-Ion Battery Charger With 50-mA LDO and 2.3-A Production Test Support SLUU358 – April 2009Submit Documentation Feedback

Vbat
Viset
V_0.1 ohm_BAT
Ven/set
Vin
Viset
Vpg
Vchg
C1
C2
C4
C3
www.ti.com Test Summary
Figure 3. Two-Pulse Programming Shows Timing of Program Change From 0.4 A to 0.1 A
Figure 4. Power-Up Sequence Shows Timing Between Vin, Viset, Vpg, and Vchg. C1: Chg @ JMP1; C4:PG @ JMP8; LEDs Pulled Up to 4.15-V Battery
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5 Schematics
Schematics www.ti.com
Figure 5. Basic EVM Charger Circuit
Figure 6. Circuit for Programming Pulse (Typically Done by Host)
1.1-A, Single-Input, Single-Cell, Li-Ion Battery Charger With 50-mA LDO and 2.3-A Production Test Support6 SLUU358 – April 2009Submit Documentation Feedback

6 Layout
www.ti.com Layout
Figure 7. Assembly Layer
Figure 8. Top Copper Layer
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7 Bill of Materials
Bill of Materials www.ti.com
Figure 9. Bottom Copper Layer Bottom View
Table 1. HPA437A Bill of Materials - bq25040Count RefDes Value Description Size Part Number MFR
1 C1 1 F Capacitor, Ceramic, 25V, X5R, 10% 0805 ECJ-2FB1E105K Panasonic
9 C2, C3, 1 F Capacitor, Ceramic, 10V, X5R, 10% 0603 ECJ-1VB1A105K PanasonicC6C12
1 C4 10 F Capacitor, Ceramic, 25V, X5R, 10% 1210 ECJ-3YB1E106K Panasonic
1 C5 47 F Capacitor, Ceramic, 10V, XR5, 20% 1210 ECJ-4YB1A476M Panasonic
2 D1, D2 LTST-C190GKT Diode, LED, Green, 2.1-V, 20-mA, 0603 LTST-C190GKT Lite On6-mcd
1 D3 BZX84C10LT1G Diode, Zener, 10-V, 350-mW SOT-23 BZX84C10LT1G On Semi
4 GND1 GND4 BLK Test Point, 0.032 Hole 5011 Keystone
3 J1J3 ED555/2DS Terminal Block, 2-pin, 6-A, 3,5mm 0.27 0.25 inch ED555/2DS OST
8 JMP1JMP8 PTC36SAAN Header, Male 2-pin, 100mil spacing, 0.100 inch 2 PTC36SAAN Sullins(36-pin strip)
1 Q1 MMBT3904LT1G Bipolar, NPN, 40-V, 200-mA,225-mW SOT23 MMBT3904LT1G On Semi
1 R1 1k Resistor, Chip, 1/16W, 1% 0603 Std Std
2 R11, R12 1.0k Resistor, Chip, 1/16W, 1% 0603 Std Std
0 R21 DNI Resistor, Chip, 1/16W, 1% 0603 Std Std
2 R3, R4 1.5k Resistor, Chip, 1/16W, 1% 0603 Std Std
3 R5, R17, R18 100k Resistor, Chip, 1/16W, 1% 0603 Std Std
1 R6 100 Resistor, Chip, 1/16W, 1% 0603 Std Std
1 R2 2k Resistor, Chip, 1/16W, 1% 0603 Std Std
1 R7 2k Potentiometer, 1/4 in. Cermet, 12-Turn, 0.25 0.17 3266W-202 BournsTop-Adjust
6 R8, R13R16, 0k Resistor, Chip, 1/16W, 1% 0603 Std StdR20
3 R9, R10, R19 10k Resistor, Chip, 1/16W, 1% 0603 Std Std
81.1-A, Single-Input, Single-Cell, Li-Ion Battery Charger With 50-mA LDO and 2.3-A Production Test Support SLUU358 – April 2009Submit Documentation Feedback

www.ti.com Bill of Materials
Table 1. HPA437A Bill of Materials - bq25040 (continued)Count RefDes Value Description Size Part Number MFR
1 S1 G12AP Switch, ON-ON Mini Toggle 0.28 0.18 inch G12AP NKK
4 TP1, TP2, WHT Test Point, O.032 Hole 5012 KeystoneTP6, TP10
1 U1 BQ25040DQC IC, 1.2A, Single-Input, 1 Cell Li-Ion TDFN-10 BQ25040DQC TICHARGER
1 U2 TPS76133DBV IC, Low-Power 100 mA LDO Regulator SOT23-5 TPS76133DBV TI
1 U3 SN74LV175APW IC, Quad D-Flip Flop with Clear TSSOP SN74LV175APW TI
1 U4 MC74HC74ADTR2G IC, Dual D Flip Flop with Set and Reset TSSOP MC74HC74ADTR2G On Semi
1 U5 SN74LVC2G132DCT IC, Dual 2-Input NAND Gate With SSOP-8 SN74LVC2G132DCTR TIR Schmitt-Trigger Inputs
1 U6 SN74HC10QPWREP IC, Triple 3-Input Positive NAND Gate TSSOP SN74HC10QPWREP TI
4 929950-00 Shunts 100 mill Black 3M
1 PCB, 1.9 In 2 In 0.031 In HPA437 Any
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EVALUATION BOARD/KIT IMPORTANT NOTICE
Texas Instruments (TI) provides the enclosed product(s) under the following conditions:This evaluation board/kit is intended for use for ENGINEERING DEVELOPMENT, DEMONSTRATION, OR EVALUATION PURPOSESONLY and is not considered by TI to be a finished end-product fit for general consumer use. Persons handling the product(s) must haveelectronics training and observe good engineering practice standards. As such, the goods being provided are not intended to be completein terms of required design-, marketing-, and/or manufacturing-related protective considerations, including product safety and environmentalmeasures typically found in end products that incorporate such semiconductor components or circuit boards. This evaluation board/kit doesnot fall within the scope of the European Union directives regarding electromagnetic compatibility, restricted substances (RoHS), recycling(WEEE), FCC, CE or UL, and therefore may not meet the technical requirements of these directives or other related directives.Should this evaluation board/kit not meet the specifications indicated in the User’s Guide, the board/kit may be returned within 30 days fromthe date of delivery for a full refund. THE FOREGOING WARRANTY IS THE EXCLUSIVE WARRANTY MADE BY SELLER TO BUYERAND IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING ANY WARRANTY OFMERCHANTABILITY OR FITNESS FOR ANY PARTICULAR PURPOSE.The user assumes all responsibility and liability for proper and safe handling of the goods. Further, the user indemnifies TI from all claimsarising from the handling or use of the goods. Due to the open construction of the product, it is the user’s responsibility to take any and allappropriate precautions with regard to electrostatic discharge.EXCEPT TO THE EXTENT OF THE INDEMNITY SET FORTH ABOVE, NEITHER PARTY SHALL BE LIABLE TO THE OTHER FOR ANYINDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES.TI currently deals with a variety of customers for products, and therefore our arrangement with the user is not exclusive.
TI assumes no liability for applications assistance, customer product design, software performance, or infringement of patents orservices described herein.
Please read the User’s Guide and, specifically, the Warnings and Restrictions notice in the User’s Guide prior to handling the product. Thisnotice contains important safety information about temperatures and voltages. For additional information on TI’s environmental and/orsafety programs, please contact the TI application engineer or visit www.ti.com/esh .No license is granted under any patent right or other intellectual property right of TI covering or relating to any machine, process, orcombination in which such TI products or services might be or are used.FCC Warning
This evaluation board/kit is intended for use for ENGINEERING DEVELOPMENT, DEMONSTRATION, OR EVALUATION PURPOSESONLY and is not considered by TI to be a finished end-product fit for general consumer use. It generates, uses, and can radiate radiofrequency energy and has not been tested for compliance with the limits of computing devices pursuant to part 15 of FCC rules, which aredesigned to provide reasonable protection against radio frequency interference. Operation of this equipment in other environments maycause interference with radio communications, in which case the user at his own expense will be required to take whatever measures maybe required to correct this interference.
EVM WARNINGS AND RESTRICTIONS
It is important to operate this EVM within the input voltage range of 0 V to 30 V and the output voltage range of 0 V to 4.25 V.Exceeding the specified input range may cause unexpected operation and/or irreversible damage to the EVM. If there are questionsconcerning the input range, please contact a TI field representative prior to connecting the input power.Applying loads outside of the specified output range may result in unintended operation and/or possible permanent damage to the EVM.Please consult the EVM User's Guide prior to connecting any load to the EVM output. If there is uncertainty as to the load specification,please contact a TI field representative.During normal operation, some circuit components may have case temperatures greater than 85 °C. The EVM is designed to operateproperly with certain components above 85 °C as long as the input and output ranges are maintained. These components include but arenot limited to linear regulators, switching transistors, pass transistors, and current sense resistors. These types of devices can be identifiedusing the EVM schematic located in the EVM User's Guide. When placing measurement probes near these devices during operation,please be aware that these devices may be very warm to the touch.
Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265Copyright © 2009, Texas Instruments Incorporated