Texas Instruments TPS60251EVM-192 User manual

1 Introduction
User's GuideSLVU209A – April 2007 – Revised June 2007
TPS60251EVM-192
Contents1 Introduction .......................................................................................... 12 Setup ................................................................................................. 23 Board Layout ........................................................................................ 64 Schematic and Bill of Materials ................................................................... 9
List of Figures
1 TPS6025x Software Screenshot .................................................................. 52 Assembly Layer ..................................................................................... 63 Top Layer Routing .................................................................................. 74 Bottom Layer Routing .............................................................................. 85 TPS60251EVM-192 Schematic ................................................................... 9
List of Tables
1 Factory EVM Jumper Settings .................................................................... 42 TPS60251EVM-192 Bill of Materials ........................................................... 10
The Texas Instruments TPS60251EVM-192 evaluation module (EVM) assists designers to evaluate theoperation and performance of the TPS60251 white LED (WLED) driver for applications that are poweredwith one Li-ion or Li-polymer cell and require two or three separate banks of WLEDs. The TPS60251contains a 1x/1.5x chargepump, as well as seven current sinks that are configured into a main displaybank of four or five WLEDs and a sub-display bank of two WLEDs. Additionally, the fifth main displayWLED can be configured to drive an aux display at up to 80 mA for backlighting a keypad or a weakcamera flash.
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2 Setup
2.1 Input/Output Connector Descriptions
Setup
This chapter describes the jumpers and connectors on the EVM, as well as how to properly connect, setup, and use the TPS60251EVM-192.
J1 – VIN
This is the positive input voltage connection to the converter. The EVM operates from any supply voltagebetween 3 V and 6 V. The leads to the input supply should be twisted and kept as short as possible tominimize EMI transmission and input voltage droop.
J2 – GND
This is the input return connection for the input power supply.
J3 – USB to GPIO ConnectorThis is the connector for the interface box. Connect the ribbon cable from the USB-to-GPIO (HPA172)interface box to this connector.
J4 – VIO
This is the positive input voltage for the I
2
C circuitry. Connect an input supply from 1.8 V to the VIN inputvoltage to set the VIL and VIH levels for the I
2
C circuitry.
J5 – VLED CATHODE DM5This is the DM5 connection for using an external aux display WLED bank. Connect the cathode(s) of theexternal aux display bank to this input.
J6 – VLED ANODE DM5This is the anode connection for using an external aux display WLED bank. Connect the anode(s) of theexternal aux display bank to this output.
JP1 – DM1
JP1 is used to connect the cathode of the DM1 LED to the DM1 pin on the TPS60251. Place a shunt onJP1 to connect the WLED to the DM1 input. Remove the shunt to measure the DM1 current or use anexternal WLED for DM1.
JP2 – DM2
JP2 is used to connect the cathode of the DM2 LED to the DM2 pin on the TPS60251. Place a shunt onJP2 to connect the WLED to the DM2 input. Remove the shunt to measure the DM2 current or use anexternal WLED for DM2.
JP3 – DM3
JP3 is used to connect the cathode of the DM3 LED to the DM3 pin on the TPS60251. Place a shunt onJP3 to connect the WLED to the DM3 input. Remove the shunt to measure the DM3 current or use anexternal WLED for DM3.
JP4 – DM4
JP4 is used to connect the cathode of the DM4 LED to the DM4 pin on the TPS60251. Place a shunt onJP4 to connect the WLED to the DM4 input. Remove the shunt to measure the DM4 current or use anexternal WLED for DM4.
JP5 – DM5
JP5 is used to connect the cathode of the DM5 LED to the DM5 pin on the TPS60251. Place a shunt onJP5 to connect the WLED to the DM5 input. Remove the shunt to measure the DM5 current or use anexternal WLED for DM5.
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2.2 Equipment Requirements
2.2.1 Personal Computer
2.2.2 Printed Circuit Board Assembly
2.2.3 USB to I
2
C Adapter
2.2.4 Software
2.2.5 Power Supplies
JP6 – DS1
JP6 – DS1
JP6 is used to connect the cathode of the DS1 LED to the DS1 pin on the TPS60251. Place a shunt onJP6 to connect the WLED to the DS1 input. Remove the shunt to measure the DS1 current or use anexternal WLED for DS1.
JP7 – DS2
JP7 is used to connect the cathode of the DS2 LED to the DS3 pin on the TPS60251. Place a shunt onJP7 to connect the WLED to the DS2 input. Remove the shunt to measure the DS2 current or use anexternal WLED for DS2.
JP8 – EN
JP8 is used as the hardware enable for the TPS60251. Place a shunt in the ON position to turn theTPS60251 on. Place a shunt in the OFF position to turn TPS60251 off. All internal register values aredefaulted to 0x00 when JP1 is placed in the OFF position.
For this EVM to operate properly, the following components must be connected and properly configured.
A computer with a USB port is required to operate this EVM. The TPS60251 interface software, which isrun on the personal computer (PC), communicates with the EVM via the PC USB port. The user sendscommands to the EVM and reads the contents of the TPS60251 internal registers through the USB port.
The TPS60251EVM-192 PCB contains the TPS60251 IC and its required external components. Thisboard contains several jumpers and connectors that allow the user to customize the board for specificoperating conditions.
The HPA172 is the link that allows the PC and the EVM to communicate. The adapter connects to the PCwith the supplied USB cable on one side and to the EVM though the supplied ribbon cable on the other.When the user writes a command to the EVM, the interface program, which is run from the PC, sends thecommand to the PC USB port. The adapter receives the USB command and converts the signal to an I
2
Cprotocol. It then sends the I
2
C signal to the TPS60251 board. When the user reads a status register fromthe EVM, the PC sends a command to read a register on the EVM. When the EVM receives thecommand, it reports the status of the register via the I
2
C interface. The adapter receives the informationon the I
2
C interface, converts it to a USB protocol, and sends it to the PC.
Texas Instruments provides software to assist the user in evaluating this EVM. To install the software,insert the enclosed CD into your computer. The software should start automatically. If it does not, go to<Start>, <Run>, and type D:\setup.exe, and click <OK> (assuming that D: is your CD drive). Check theTPS60251 product folder on the TI Web site for the latest version of the software.
The TPS60251 EVM requires two power supplies for operation.
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2.3 Operation
2.3.1 TPS6025x Software Operation
2.3.1.1 Display Enable Settings
2.3.1.2 Current Level Settings
JP8 – EN
The following steps must be followed before the EVM can be operated.1. Install the TPS6025xEVM software.2. Configure all EVM jumpers to the factory settings in Table 1 .3. Connect the ribbon cable between the EVM and the USB-TO-GPIO (HPA172) adapter.4. Connect the USB cable between the computer and USB-TO-GPIO adapter.5. Connect the input voltages to the EVM.6. Run the TPS6025xEVM software.
Table 1. Factory EVM Jumper Settings
Jumper Shunt Location
JP1 InstalledJP2 InstalledJP3 InstalledJP4 InstalledJP5 InstalledJP6 InstalledJP7 InstalledJP8 Between ON and EN
The software is designed to work with the entire TPS6025x family of devices. A screenshot of the softwareis shown in Figure 1 . The software should automatically detect which device the user is trying to operateand select the correct features accordingly. If the software is started before the EVM is connected, thecorrect device may not be detected. If this occurs, the different modes are selectable using the Toolspulldown menu.
When in the TPS60251 mode, the value of Ris (R3) is selectable. The EVM comes with a 562-k Ωresistorinstalled at R3, which sets the maximum current to 25.5 mA. R3 may be replaced with a resistor valuebetween 562 k Ωand 5 M Ωto change the maximum current. If R3 is replaced, change the value for Ris inthe software, and the current level settings are automatically updated.
This portion of the software allows the user to enable/disable the different banks of LEDs using simplepushbuttons. Open lamp detection may be enabled/disabled using the provided pushbutton. Refer to theTPS60251 data sheet for a description of the open lamp detection. Additionally, a pulldown box isavailable to control the aux display settings. The aux display may be grouped with main display or set forthe separate high-current (80 mA) aux display. When using the high-current setting, it is suggested thatseparate LEDs are connected between the J5 (cathode connection) and J6 (anode connection)connectors. The LEDs installed on the EVM are rated for 30-mA dc current and may be damaged at thehigher current. Selecting the shutdown option in the Aux Display pulldown menu disables all of the LEDsand places the IC in a low-power shutdown mode. The internal registers are not changed in this mode.
This portion of the software allows the user to select the LED current for each of the banks of LEDs. Notethat when the aux display is "Grouped with Main Display", the current level for both the aux display andthe main display is adjusted with the main display pulldown box. The values in the pulldown boxes changebased on the selected value for Ris.
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2.3.1.3 General Device Settings
2.3.1.4 Device Register Map
JP8 – EN
This portion of the software allows the user to select the address of the device used. The EVM comesinstalled with the primary address device installed. Contact the factory for the secondary address deviceavailability. The mode select allows the user to set the mode of the TPS60251 chargepump. Refer to thedata sheet for the description of the available modes.
This portion of the software allows the user to change the registers on a bit level. When selecting a bit inthe register map, the description of the bit is shown on the bottom bar of the software.
Figure 1. TPS6025x Software Screenshot
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3 Board Layout
3.1 Layout
Board Layout
This chapter provides the TPS60251EVM-192 board layout and illustrations.
Board layout is critical for all switch mode power supplies. Figure 2 through Figure 4 show the boardlayout for the TPS60251EVM-192 PWB.
Figure 2. Assembly Layer
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Board Layout
Figure 3. Top Layer Routing
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Board Layout
Figure 4. Bottom Layer Routing
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4 Schematic and Bill of Materials
4.1 Schematic
Schematic and Bill of Materials
This chapter provides the TPS60251EVM-192 schematic and bill of materials.
Figure 5. TPS60251EVM-192 Schematic
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4.2 Bill of Materials
Related Documentation From Texas Instruments
Table 2. TPS60251EVM-192 Bill of Materials
Count RefDes Value Description Size Part Number MFR
Capacitor, Ceramic, 25V, X5R,1 C1 1.0uF 0603 GRM188R61E105KA12 muRata10%
Capacitor, Ceramic, 10V, X5R,2 C2, C3 2.2uF 0603 GRM188R61A225KE34 muRata10%
Capacitor, Ceramic, 10V, X5R,1 C4 4.7uF 0805 GRM21BR61A475KA73 muRata10%5 DM1 - DM5 Diode. LED, White 0.079 ×0.118 NSSW100CT Nichia2 DS1, DS2 Diode. LED, White 0.079 ×0.118 NSSW100CT NichiaJ1, J2, J4, J5, Header, 2 pin, 100mil spacing,5 0.100 ×2 PTC36SAAN SullinsJ6 (36-pin strip)Connector, Male Straight 2 ×51 J3 0.338 ×0.788 2510-6002UB 3Mpin, 100mil spacing, 4 WallHeader, 2 pin, 100mil spacing,7 JP1 - JP7 0.100 ×2 PTC36SAAN Sullins(36-pin strip)Header, 3 pin, 100mil spacing,1 JP8 0.100 ×3 PTC36SAAN Sullins(36-pin strip)2 R1, R2 10.0k Resistor, Chip, 1/16W, 1% 0603 STD STD1 R3 562k Resistor, Chip, 1/16W, 1% 0603 STD Std2 R4, R5 1.0k Resistor, Chip, 1/16W, 1% 0603 STD STDIC, Hi-Efficiency Charge Pump,1 U1 QFN-24 TPS60251RTW TIWLED driversPCB, 2.25 In ×1.95 In ×0.0621 -- HPA192 AnyIn8 -- Shunt, 100mil, Black 0.100 929950-00 3M
Related Documentation From Texas InstrumentsTPS60251 data sheet (SLVS767)
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