Datasheet

SS
FB
SS
t (ms) =
C6(nF) V 1.1
C6(nF) 0.765 1.1
=
I (μA) 6
´ ´
´ ´
SW
VBST
EN
VFB
GND
VO
4
5
6
2
1
7
VIN
SS
VIN
VREG5
EN
Logic
SW
PGND
Protection
Logic
Ref
SS
UVLO
UVLO
Softstart
SS
REF
TSD
Ref
VREG5
8
VIN
Ceramic
Capacitor
3
SGND
SGND
PGND
PWM
+
-
+
OCP
+
-
VREG5
XCON
VREG5
Control Logic
1 shot
ON
SW
PGND
ZC
+
-
TPS54528
www.ti.com SLVSAY4C –JULY 2011–REVISED MARCH 2014
8 Detailed Description
8.1 Overview
The TPS54528 is a 5-A synchronous step-down (buck) converter with two integrated N-channel MOSFETs. It
operates using D-CAP2™ mode control. The fast transient response of D-CAP2™ control reduces the output
capacitance required to meet a specific level of performance. Proprietary internal circuitry allows the use of low
ESR output capacitors including ceramic and special polymer types.
8.2 Functional Block Diagram
8.3 Feature Description
8.3.1 Soft Start And Pre-Biased Soft Start
The soft start function is adjustable. When the EN terminal becomes high, 6 μA current begins charging the
capacitor which is connected from the SS terminal to GND. Smooth control of the output voltage is maintained
during start up. The equation for the slow start time is shown in Equation 1. VFB voltage is 0.765 V and SS
terminal source current is 6μA.
(1)
Copyright © 2011–2014, Texas Instruments Incorporated 9
Product Folder Links: TPS54528