Texas Instruments TPS51124 User manual

User’s Guide
TPS51124 Buck Controller Evaluation Module User's
Guide
Table of Contents
1 Description.............................................................................................................................................................................. 2
2 Electrical Performance...........................................................................................................................................................2
3 Schematic................................................................................................................................................................................3
4 Test Setup and Results.......................................................................................................................................................... 4
4.1 Test Setup.......................................................................................................................................................................... 4
4.2 Test Procedure................................................................................................................................................................... 4
4.3 Start-Up Performance........................................................................................................................................................ 5
4.4 Transient Performance.......................................................................................................................................................5
5 Configuration.......................................................................................................................................................................... 6
5.1 Switching Frequency Selection.......................................................................................................................................... 6
5.2 Bootstrap Diode Selection..................................................................................................................................................6
6 EVM Assembly Drawing and PCB Layout............................................................................................................................ 7
7 List of Materials.....................................................................................................................................................................10
8 References.............................................................................................................................................................................11
9 Revision History....................................................................................................................................................................11
Trademarks
D-CAP™ is a trademark of Texas Instruments.
All trademarks are the property of their respective owners.
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TPS51124 Buck Controller Evaluation Module User's Guide 1
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1 Description
The TPS51124 is a dual, adaptive on-time D-CAP™ mode synchronous buck controller. The part enables system
designers to cost-effectively complete the suite of notebook power bus regulators with the absolute lowest
external component count and lowest standby consumption. The fixed frequency emulated adaptive on-time
control supports seamless operation between PWM mode at heavy load condition and reduced frequency
operation at light load for high efficiency down to milli-ampere range. The main control loop for the TPS51124
uses D-CAP mode that is optimized for low-ESR output capacitors such as POSCAP or SP-CAP promises fast
transient response with no external compensation. Simple and separate power-good signals for each channel
allow flexibility of power sequencing. The part provides a convenient and efficient operation with supply input
voltages (V5IN, V5FILT) ranging from 4.5 V to 5.5 V, conversion voltages (drain voltage for the synchronous
high-side MOSFET) from 3 V to 28 V, and output voltages from 0.76 V to 5.5 V.
The HPA178 (TPS51124EVM) evaluation module is a high efficiency, dual synchronous buck converter providing
1.05 V at 10 A and 1.5 V at 10 A from 5-V to 25-V input. This user’s guide describes the HPA178 performance in
medium switching frequency.
2 Electrical Performance
SPECIFICATIONS TEST CONDITIONS MIN TYP MAX UNIT
Input voltage range (V5IN) 4.5 5.0 5.5 V
Input voltage range (VIN) 5 12 25 V
CH1
Output voltage 1.05 V
Operating frequency TONSEL: Float
VIN = 12 V, IOUT1 = 10 A 300 kHz
Output current 10 A
Overcurrent limit VIN = 12 V 13 A
Output ripple voltage VIN = 12 V,IOUT = 10 A 35 mVp-p
CH2
Output voltage 1.5 V
Operating frequency TONSEL: Float
VIN = 12 V, IOUT2 = 10 A 360 kHz
Output current 10 A
Overcurrent limit VIN = 12 V 13 A
Output ripple voltage VIN = 12 V, IOUT2 = 10 A 35 mVp-p
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3 Schematic
Figure 3-1. TPS51124 EVM Schematic Diagram
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4 Test Setup and Results
4.1 Test Setup
Connect the test equipment and HPA178 EVM board as shown in Figure 4-1.
HPA178
TPS51124EVM-001
+
-Electronic
Load2
Oscilloscope
CH2
Electronic
Load1
+
-
Oscilloscope
CH1
VO1
VO1_GND
VO2
VO2_GND
12V/10A
Power supply
VIN
_GND
VIN
+-
DMM3
+
-
DMM2
+
-
DMM1
+
-
V5IN
_GND
V5IN CN1
CN2
+ -
DMM4
+ -
5V/1A
Power supply
TP7
TP8
TP4
TP10 TP5
TP6
TP3
TP9
FAN
Figure 4-1. Equipment Setup for HPA178 EVM Board
4.2 Test Procedure
1. Ensure the switches SW1 (EN1) and SW2 (EN2) are in the “OFF” position.
2. Ensure the shunt jumper for JP1 is set 3-pin to 4-pin (Med).
3. Apply appropriate V5IN voltage to V5IN and V5IN_GND terminals.
4. Apply appropriate VIN voltage to VIN and VIN_GND terminals.
5. Turn on SW1 (EN1). The CH1-output will start up.
6. Turn on SW2 (EN2). The CH2-output will start up.
Test Setup and Results www.ti.com
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4.3 Start-Up Performance
Figure 4-2. 1.05-V Start-Up Performance Figure 4-3. 1.5-V Start-Up Performance
4.4 Transient Performance
Figure 4-4. 1.05-V Load Transient Performance Figure 4-5. 1.5-V Load Transient Performance
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TPS51124 Buck Controller Evaluation Module User's Guide 5
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5 Configuration
This EVM could be set to the desired configurations of the user.
Please refer to the following specific configuration setting sections.
5.1 Switching Frequency Selection
Switching frequency can be set by the TONSEL pin using JP1 on the EVM. The default setting is medium.
Table 5-1. Switching Frequency Selection
Jumper (JP1) Set to TONSEL Frequency(1)
Typ CH1 CH2
Top(1-2 pin shorted) GND Slow 240 kHz 300 kHz
CENTER(3-4 pin shorted) Float Medium 300 kHz 360 kHz
Bottom(5-6 pin shorted) V5FILT Fast 360 kHz 420 kHz
(1) Frequencies are approximate.
5.2 Bootstrap Diode Selection
Bootstrap diodes (D1, D2) are not populated on this EVM since the TPS51124 has them built in. External
Schottky diodes can be added in order to further improve the efficiency.
Configuration www.ti.com
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6 EVM Assembly Drawing and PCB Layout
Figure 6-1. Top Assembly
Figure 6-2. Top Layer
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Figure 6-3. Inner Layer 1
Figure 6-4. Inner Layer 2
EVM Assembly Drawing and PCB Layout www.ti.com
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Figure 6-5. Bottom Layer
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7 List of Materials
Reference
Designator
QTY Description Size Mfr Part Number
— 1 Shunt,100-mil, Black 0.100 3M 929950-00
C1 0 Capacitor,Aluminum 0.26 × 0.26 inch Any Any
C13, C14 2 Capacitor, POSCAP, 330 mF, 2.5-
V18-mW, 20%
7343 SANYO 2R5TPE330MI
C15 1 Capacitor,Ceramic, 4.7 mF,6.3 V, BJ,
20%
0805 TDK C2012X5R0J475K
C16 1 Capacitor,Ceramic, 1 mF,6.3 V, BJ,
20%
0805 TDK C2012X5R0J105K
C17 1 Capacitor,Ceramic, 18 pF, 50 V, BJ,
20%
0805 Std Std
C2, C3, C4, C5 4 Capacitor,Ceramic, 10 mF,25 V, BJ ,
20%
1210 TDK /
TaiyoYuden
C3225JB1E106 /
TMK325BJ106MM
C6, C11 2 Capacitor,Ceramic, 0.1 mF,50 V, BJ,
20%
0805 Std Std
C7, C8 2 Capacitor, POSCAP, 330 mF, 2.5-
V15-mW, 20%
7343 SANYO 2R5TPE330MF
C9, C10, C12, C18 0 Capacitor,Ceramic 0805 Any Any
CN1, CN2 2 Adaptor, 3.5-mm probe clip (or
131-5031-00)
0.2 Tektronix 131-4244-00
D1, D2 0 Diode,Schottky, 0.5 A, 30 V SOD-123 Any Any
J1, J2 2 TerminalBlock, 2-pin, 15 A, 5.1 mm 0.40 × 0.35 inch OST ED1609
JP1 1 Header, 2×3-pin,100mil spacing (36-
pin strip)
0.20 × 0.30 inch Sullins PTC36DAAN
L1, L2 2 Inductor,1.0 μH, 20.5 A, 2 mW 0.496 × 0.532 inch TOKO FDA1254-1R0M
Q1, Q3 2 MOSFET,N-ch, 30 V, 11 A, 12.5 mW SO8 IR IRF7821
Q2, Q4 2 MOSFET,N-ch, 30 V, 13.8 A, 6.8 mW SO8 IR IRF8113
R1, R7 2 Resistor,Chip, 100 kW,1/10W, 1% 0805 Std Std
R12, R13 0 Resistor,Chip 0805 Std Std
R2, R9, R10 3 Resistor,Chip, 3.3 W,1/10W, 1% 0805 Std Std
R3 1 Resistor,Chip, 28.7 kW,1/10W, 1% 0805 Std Std
R4, R6 2 Resistor,Chip, 75 kW,1/10W, 1% 0805 Std Std
R5 1 Resistor,Chip, 73.2 kW,1/10W, 1% 0805 Std Std
R8, R11 2 Resistor,Chip, 6.8 kW,1/10W, 1% 0805 Std Std
SW1, SW2 2 Switch,ON-ON Mini Toggle 0.28 × 0.18 inch Nikkai G12AP
TP1, TP2 2 Testpoint, White, Thru hole 0.125× 0.125 inch Keystone 5012
TP10 1 Testpoint, Orange, Thru hole 0.125× 0.125 inch Keystone 5013
TP3, TP4, TP5, TP6 4 Testpoint, Black, Thru hole 0.125× 0.125 inch Keystone 5011
TP7, TP8 2 Testpoint, Yellow, Thru hole 0.125× 0.125 inch Keystone 5014
TP9 1 Testpoint, Red, Thru hole 0.125× 0.125 inch Keystone 5010
U1 1 IC, Dual Synchronous Step-Down
Controller for Low Voltage Power
Rails
QFN32 TI TPS51124RHB
VIN_GND,VIN,
V5IN,V5IN_GND
4 Pin,Wiring Terminal 0.09(D) × 0.31 inch MillMax 3183-2-00-15-00-
00-080
List of Materials www.ti.com
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