TPS5103_08 Datasheet, PDF (1/40 Pages) Texas Instruments – MULTIPLE MODE SYNCHRONOUS DC/DC CONTROLLER

TPS5103
MULTIPLE MODE SYNCHRONOUS DC/DC CONTROLLER
D Step-Down DC-DC Converter
D Three Operation-Modes
– Heavy Load:
– Fixed Frequency PWM
– Hysteretic (User Selectable)
– Light Load:
– Skip Mode
D 4.5-V to 25-V Input Voltage Range
D Adjustable Output Voltage Down to 1.2 V
D 95% Efficiency
D Standby Control
D Overcurrent Protection
D UVLO for Internal 5-V Regulation
D Low-Standby Current . . . 0.5 mA Typical
D T_A = –40°C to 85°C
SLVS240A – SEPTEMBER 1999 – REVISED MAY 2001
DB PACKAGE
(TOP VIEW)
SOFTSTART 1
INV 2
FB 3
C_T 4
R_T 5
GND 6
REF 7
COMP 8
PWM/SKIP 9
STBY ¹⁰
20 LH
19 OUT_u
18 LL
17 OUT_d
16 OUTGND
15 TRIP
14 VCC_SENSE
13 V_CC
12 VREF5
11 _{VREG5V_IN}
description
The TPS5103 is a synchronous buck dc/dc controller, designed for notebook PC system power. The controller
has three user-selectable operation modes available: hysteretic mode, fixed-frequency PWM control, or SKIP
control.
In high-current applications, where fast transient response is advantageous for reducing bulk capacitance, the
hysteretic mode is selected by connecting the R_T pin to VREF5. Selecting the PWM/SKIP modes for less
demanding transient applications is ideal for conserving notebook battery life under light load conditions. The
device includes high-side and low-side MOSFET drivers capable of driving low r_ds(on) N-channel MOSFETs.
The user-selectable overcurrent protection (OCP) threshold is set by an external TRIP-pin resistor in order to
protect the system. The TPS5103 is configured so that a current-sense resistor is not required, improving the
operating efficiency.
C4
5V
C1
R2
C2
R1
U1
TPS5103
1
20
SOFTSTART
LH
2 _INV
3
19
OUT_u ₁₈
FB
4
5
6
CT
RT
LL ₁₇
OUT_d ₁₆
OUTGND ₁₅
GND
TRIP
7 _REF
8
14
VCC_SENSE ₁₃
COMP
9 _PWM/SKIP
VCC ₁₂
VREF5
10 _STBY
11
VREG5V_IN
D1
C3
R3
R4
Q1
OUTPUT
L1
C5 ⁺
Q2
Figure 1. Typical Design
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
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Copyright  2001, Texas Instruments Incorporated
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