Datasheet
Introduction
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1 Introduction
The TPS51125A is a cost effective, dual-synchronous buck controller targeted for notebook system power
supply solutions. It provides 5-V and 3.3-V LDOs and requires few external components. The 270-kHz
VCLK output can be used to drive an external charge pump, generating gate drive voltage for the load
switches without reducing the main converter's efficiency. The TPS51125A supports high-efficiency, fast
transient response and provides a combined power-good signal. Out-of-Audio™ mode light-load operation
enables low acoustic noise at much higher efficiency than conventional forced PWM operation. Adaptive
on-time D-CAP™ control provides convenient and efficient operation. The part operates with supply input
voltages ranging from 5.5 V to 28 V and supports output voltages from 2 V to 5.5 V.
TPS51125AEVM evaluation module is a high efficiency, dual synchronous buck converter providing 5 V at
8 A and 3.3 V at 8 A from 8-V to 25-V input.
2 Performance Specification Summary
Table 1 gives the EVM performance specifications and qualifications.
Table 1. Performance Specification Summary
SPECIFICATION TEST CONDITIONS MIN TYP MAX UNITS
V
IN
Input voltage range Voltage applied to VBAT 8 25 V
CHANNEL1
V
OUT
Output voltage 5 V
f Operating frequency V
TONSEL
= V
VREF
, V
VIN
= 12 V, I
OUT
= 6 A 245 kHz
I
OUT
Output current 8 V ≤ V
VIN
≤ 25 V 8 A
I
OC
Overcurrent limit V
VIN
= 12 V 10
CHANNEL2
V
OUT
Output voltage 3.3 V
f Operating frequency V
TONSEL
= V
VREF
, V
VIN
= 12 V, I
OUT
= 6 A 305 kHz
I
OUT
Output current 8 V ≤ V
VIN
≤ 25 V 8 A
I
OC
Overcurrent limit V
VIN
= 12 V 10
2
High Performance Synchronous Buck EVM Using the TPS51125A SLUU408–FEBRUARY 2010
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