nx2147 Microsemi Corporation, nx2147 Datasheet - Page 5

• Manufacturer Part Number: nx2147
• Description: Single Channel Mobile Pwm Controller With Dynamic Voltage Adjustment
• Manufacturer: Microsemi Corporation

PIN DESCRIPTIONS
Rev. 1.6
03/09/09
Rev. 1.8
12/28/09
PIN NUMBER PIN SYMBOL
10
11
12
13
14
15
16
17
1
2
3
4
5
6
7
8
9
VREF_OC
ENSW/
GPIO1
GPIO0
MODE
PGND
VOUT
PVCC
HDRV
LDRV
VCC
TON
BST
PAD
SW
VP
D1
D0
This pin is directly connected to the output of the switching regulator and
senses the VOUT voltage. An internal MOSFET with 20ohms rdson dis-
charges the output during turn off.
This pin supplies the internal 5V bias circuit. A 1uF X7R ceramic capacitor is
placed as close as possible to this pin and ground pin.
This pin is connected via resistor divider to VREF_OC pin to set the output
DC voltage from 0.5V to VREF 2.5V.
This pin is a drain of an internal signal MOSFET. When it is connected via
resistor to the VP pin,and the GPIO0 pin is set low, it reduces the VP
voltage by paralleling this resistor to the fixed resistor from VP to GND.
This pin is a drain of an internal signal MOSFET. When it is connected via
resistor to the VP pin,and the GPIO_1 pin is set low, it reduces the VP
voltage by paralleling this resistor to the fixed resistor from VP to GND.
A logic level input signal that controls the D1 pin. A low signal turns the
internal D1 MOSFET on and a High turns it off.
Power ground.
Low side gate driver output.
Provide the voltage supply to the lower MOSFET drivers. Place a high
frequency decoupling capacitor 1uF X5R to this pin.
Reference output voltage. A resistor divider from this pin to VP pin sets the
output voltage. The total resistance from this pin to GND also sets the OCP
threshold voltage. Note that when GPIO0 and GPIO1 pins are high the
reference divider is at its highest voltage. The nominal voltage of Vref is
2.5V.
This pin is connected to source of high side FETs and provide return path for
the high side driver. It is also the input of zero current sensing comparator.
High side gate driver output.
This pin supplies voltage to high side FET driver. A high freq 1uF X7R
ceramic capacitor and 2.2ohm resistor in series are recommended to be
placed as close as possible to and connected to this pin and SW pin.
A logic level input signal that controls the D0 pin. A low signal turns the
internal D0 MOSFET on and a High turns it off.
Switching converter enable input. Connect to VCC for PFM/Non synchronous
mode, connected to an external resistor divider equals to 70%VCC for ultra-
sonic, connected to GND for shutdown mode, floating or connected to 2V for
the synchronous mode.
VIN sensing input. A resistor connects from this pin to VIN will set the fre-
quency. A 1nF capacitor from this pin to GND is recommended to ensure the
proper operation.
Analog ground.
PIN DESCRIPTION
NX2147
5