TPS51123A Datasheet, PDF (7/36 Pages) Texas Instruments – Dual-Synchronous, Step-Down Controller with Out-of-Audio™ Operation and 100-mA LDOs for Notebook System Power

www.ti.com
TERMINAL
NAME
NO.
DRVH1
21
DRVH2
10
DRVL1
19
DRVL2
12
EN0
13
ENC
18
GND
15
LL1
20
LL2
11
PGOOD
23
SKIPSEL
14
TRIP1
1
TRIP2
6
TONSEL
4
VBST1
22
VBST2
9
VFB1
2
VFB2
5
VIN
16
VO1
24
VO2
7
VREF
3
VREG3
8
VREG5
17
TPS51123A
DEVICE INFORMATION
Table 2.
SLUSAA6B – APRIL 2011 – REVISED MARCH 2012
I/O
DESCRIPTION
O
High-side N-channel MOSFET driver outputs. LL referenced drivers.
O
Low-side N-channel MOSFET driver outputs. GND referenced drivers.
Master enable input.
I/O Open : LDOs on, and ready to turn both switcher channels.
GND : disable all circuit
I
Channel 1 and Channel 2 enable input. Pull up to the voltage ranging 3.3-V to 5-V to turn on both
switcher channels. Short to ground to shutdown them.
–
Ground.
I
Switch node connections for high-side drivers, current limit and control circuitry.
O
Powergood window comparator output for channel 1 and 2. (Logical AND)
Selection pin for operation mode:
I
OOA auto skip : Connect to VREG3 or VREG5
PWM only: Connect to VREF
Auto skip: Connect to GND
I/O
Channel 1 and Channel 2 enable and OCL trip setting pins. Connect resistor from this pin to GND to
set threshold for synchronous R_DS(on) sense. Short to ground to shut down a switcher channel.
On-time adjustment pin.
365 kHz/460 kHz setting: connect to VREG5
I
300 kHz/375 kHz setting: connect to VREG3
245 kHz/305 kHz setting: connect to VREF
200 kHz/250 kHz setting: connect to GND
I
Supply input for high-side N-channel MOSFET driver (boost terminal).
I
SMPS feedback inputs. Connect with feedback resistor divider.
I
High voltage power supply input for 5-V/3.3-V LDO.
I/O
Output connection to SMPS. These terminals work as fixed voltage inputs and output discharge
inputs. VO1 and VO2 also work as 5-V and 3.3-V switch over return power input respectively.
O
2-V reference voltage output. Connect a high-quality X5R or X7R ceramic capacitor with a value
between 220-nF and 1-µF to signal GND near the device.
O
3.3-V power supply output. Connect a high-quality X5R or X7R ceramic capacitor with a value of 10-
µF or larger to power GND near the device. A 1-μF ceramic capacitor is acceptable when not loaded.
O
5-V power supply output. Connect a high-quality X5R or X7R ceramic capacitor with a value of 10-µF
or larger to power GND near the device.
Copyright © 2011–2012, Texas Instruments Incorporated
Product Folder Link(s): TPS51123A
Submit Documentation Feedback
7