SMB113A/B/SMB117/A
Preliminary Information
PIN DESCRIPTION
Pin Number
Pin Type
Pin Name
Pin Description
The HSDRV_CH0 (Channel 0 High-side Driver) pin is the upper
switching node of the channel 0 synchronous step-down buck
controller. Attach to the gate of p-channel MOSFET. A delay
exists between the assertion of HSDRV_CH0 and assertion of
LSDRV_CH0 to prevent excessive current flow during switching.
1
OUT
HSDRV_CH0
The HEALTHY pin is an open drain output. High when all
enabled output supplies are within the programmed levels.
HEALTHY will ignore any disabled supply.
There is a
programmable glitch filter on the under-voltage and over-voltage
sensors so that short transients outside of the limits will be
ignored by HEALTHY. This pin can also be programmed to act
as a Reset Output (nRESET). In this case, it releases with a
programmable delay after all outputs are valid. When used, this
pin should be pulled high by an external pull-up resistor.
HEALTHY
(nRESET)
2
3
OUT
IN
The COMP1_CH0 (Channel 0 primary Compensation) pin is the
primary feedback input of the channel 0 step-down buck
controller. The COMP1_CH0 pin is internally connected to a
programmable resistor divider.
COMP1_CH0
The COMP2_CH0 (Channel 0 secondary Compensation) pin is
the secondary feedback input of the channel 0 step-down buck
controller.
4
5
IN
IN
COMP2_CH0
VM_CH0
The VM_CH0 (Channel 0 Voltage Monitor) pin connects the
channel 0 step-down controller output. Internally the VM_CH0 pin
connects to a programmable resistor divider.
SDA (Serial Data) is an open drain bi-directional pin used as the
6
7
I/O
IN
SDA
SCL
I2C data line. SDA must be tied high through a pull-up resistor.
SCL (Serial Clock) is an open drain input pin used as the I2C
clock line. SCL must be tied high through a pull-up resistor.
The LSDRV_CH1 (Channel 1 Low-side Driver) pin is the lower
switching node of the channel 1 synchronous step-down buck
controller. Attach to the gate of n-channel MOSFET.
8
9
OUT
LSDRV_CH1
HVSUP1
PWR
Channel 1 High Voltage Supply for Channel 1 buck driver.
The HSDRV_CH1 (Channel 1 High-side Driver) pin is the upper
switching node of the channel 1 synchronous step-down buck
controller. Attach to the gate of p-channel MOSFET. A delay
exists between the assertion of HSDRV_CH1 and assertion of
LSDRV_CH1 to prevent excessive current flow during switching.
The HOST_RESET pin is an active high reset input. When this
pin is asserted high, the nRESET output will immediately go low.
When HOST_RESET is brought low, nRESET will go high after a
programmed reset delay. When pin 2 is used as a HEALTHY
output, this pin needs to be attached to GND or VBATT via a
resistor.
10
11
OUT
IN
HSDRV_CH1
HOST_RESET
The COMP1_CH1 (Channel 1 primary Compensation) pin is the
primary compensation input of the channel 1 step-down buck
controller. The COMP1_CH1 pin is internally connected to a
programmable resistor divider.
12
13
IN
IN
COMP1_CH1
COMP2_CH1
The COMP2_CH1 (Channel 1 secondary Compensation) pin is
the secondary compensation input of the channel 1 step-down
buck controller.
Summit Microelectronics, Inc
2111 2.4 6/24/2008
5
SUMMIT [ SUMMIT MICROELECTRONICS, INC. ]
