Datasheet

R
PD
input
buffer
PD_x
EN_internal /
VSELx_internal
EN /
VSELx
TPS62360, TPS62361B
TPS62362, TPS62363
SLVSAU9C –MAY 2011–REVISED NOVEMBER 2012 www.ti.com
Slave Address Byte
MSB LSB
X X X X X X A1 A0
The slave address byte is the first byte received following the START condition from the master device.
Register Address Byte
MSB LSB
0 0 0 0 0 D2 D1 D0
Following the successful acknowledgment of the slave address, the bus master will send a byte to the
TPS6236x, which will contain the address of the register to be accessed.
I
2
C REGISTER RESET
The I
2
C registers can be reset by pulling VDD below the VDD Under Voltage Level, V
DD,UVLO
. VDD can be used
as a hardware reset function to reset the registers to defaults, if VDD is supplied by a GPIO of the host. The
host's GPIO must be capable of driving I
VDD,max
.
Refer to the Input Under Voltage Protection section for details.
PULL DOWN RESISTORS
The EN, VSEL0 and VSEL1 inputs feature internal pull down resistors to discharge the potential if one of the pins
is not connected or is triggered by a high impedance source. See Figure 48. By default, the pull down resistors
are enabled.
Figure 48. Pull Down Resistors at EN, VSEL0 and VSEL1 Pins
If a pin is read as a logic HIGH, its pull down resistor is disconnected dynamically to reduce power consumption.
To achieve lowest possible quiescent current or if external pull up/down resistors are employed, the internal pull
down resistors can be disabled individually at EN, VSEL0 and VSEL1 by I
2
C programming the registers PD_EN,
PD_VSEL0 and PD_VSEL1.
INPUT CAPACITOR SELECTION
The input capacitor is required to buffer the pulsing current drawn by the device at VIN and reducing the input
voltage ripple. The pulsing current is originated by the operation principles of a step down converter.
Low ESR input capacitors are required for best input voltage filtering and minimal interference with other system
components. For best performance, ceramic capacitors with a low ESR at the switching frequency are
recommended. X7R or X5R type capacitors should be used.
A ceramic input capacitor in the nominal range of C
IN
= 10µF to 22µF should be a good choice for most
application scenarios. In general, there is no upper limit for increasing the input capacitor.
For typical operation, a 10µF X5R type capacitor is recommended. DC bias effects reduce the effective
capacitance of MLCC capacitors as a function of the voltage applied. This effect needs to be factored in when
choosing an input capacitor by choosing the proper voltage rating. Table 7 shows a list of recommended
capacitors.
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