TPS22994 Datasheet, PDF (18/44 Pages) Texas Instruments – Quad Channel Load Switch with GPIO and I2C Control

TPS22994
SLVSCL4B – AUGUST 2014 – REVISED SEPTEMBER 2014
9 Detailed Description
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9.1 Overview
The TPS22994 is a GPIO controllable and I²C programmable, quad-channel load switch. The device comes in a
20-pin QFN package and is designed to handle up to 3.6 V and 1 A per channel (per VINx/VOUTx). The VBIAS
pin of the device is designed to interface directly with battery voltages or adapter input voltages as high as 17.2
V. To increase efficiency during standby power, the device implements each channel with an N-channel
MOSFET without the use of a chargepump. This allows the quiescent current (I_Q,VBIAS) to be much lower than
traditional GPIO-based load switches, thus increasing efficiency during standby.
The TPS22994 can be programmed via standard I²C commands. This allows the user to select between 5 slew
rates, 4 on-delays, and 4 quick output discharge (QOD) options. The combination of these options allows the
user to program the power sequencing for downstream modules via software. Each individual channel can also
be controlled (enabling and disabling channels only) via GPIO when I²C communication is not present. The
TPS22994 contains a special function called SwitchALL^TM that allows multiple devices (either the TPS22993 or
TPS22994) to be enabled or disabled synchronously via a single I²C command, allowing the user to switch
system power states synchronously.
9.2 Functional Block Diagram
VBIAS
Power supply
and bandgap
Driver
ON1
ON2
ON3
ON4
ADD1
ADD2
ADD3
VDD
SCL
SDA
GPIO ON
Buffer
Address
Buffers &
Level Shifters
I2C
SCL/SDA
Buffers &
Level Shifters
PD_EN
Driver
I2C
Digital Control
PD_EN
Driver
PD_EN
Driver
* PD_EN = Pulldown Enable
PD_EN
VIN1
VOUT1
VIN2
VOUT2
VIN3
VOUT3
VIN4
VOUT4
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