TPS5103
MULTIPLE MODE SYNCHRONOUS DC/DC CONTROLLER
SLVS240 鈥?SEPTEMBER 1999
D
D
D
D
D
D
D
D
D
D
Step-Down DC-DC Converter
Three Operation-Mode
鈥?Heavy Load:
鈥?Fixed Frequency PWM
鈥?Hysteretic (User Selctable)
鈥?Light Load:
鈥?Skip Mode
4.5 V to 25 V Input Voltage Range
Adjustable Output Voltage Down to 1.2 V
95% Efficiency
Stand-By Control
Over Current Protection
UVLO for Internal 5 V Regulation
Low Standby Current . . . 0.5 mA Typical
T
A
= 鈥?0擄C to 85擄C
DB PACKAGE
(TOP VIEW)
SOFTSTART
INV
FB
C
T
R
T
GND
REF
COMP
PWMSKIP
STBY
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
LH
OUT_u
LL
OUT_d
OUTGND
TRIP
VCC_SENSE
VCC
VREF5
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 Rt 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 Rds (on) N鈥揷hannel MOSFETs.
The user-selectable overcurrent protection (OCP) threshold is set by an external TRIP pin resister in order to
protect the system. The TPS5103 is configured so that a current sense resistor is not required, improving the
operating efficiency.
5V
R1
C1
1
2
3
4
5
6
7
8
9
10
C4
U1
TPS5103
SOFTSTART
LH
INV
OUTU
FB
LL
CT
OUTD
RT
OUTGND
GND
TRIP
REF
VCCSENSE
COMP
VCC
PWM/SKIP
VREF5
STBY
VREG5V_IN
20
19
18
17
16
15
14
13
12
11
D1
C3
R3
Q1
L1
C5
Q2
+
OUTPUT
R2
R4
C2
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.
TI is a trademark of Texas Instruments Incorporated.
PRODUCT PREVIEW information concerns products in the formative or
design phase of development. Characteristic data and other
specifications are design goals. Texas Instruments reserves the right to
change or discontinue these products without notice.
Copyright
漏
1999, Texas Instruments Incorporated
POST OFFICE BOX 655303
鈥?/div>
DALLAS, TEXAS 75265
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