PIN CONNECTIONS
PIN CONNECTIONS
FREQ
INV
VOUT
VIN2
VIN2
SW
1
CLKSYN
CLKSEL
RST
RT
EN2
32
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
2
3
4
5
6
EN1
7
SW
ADDR
GND
GND
VDD1
VIN1
LDRV
CS
LDO
LFB
LCMP
8
GND
GND
PGND
PGND
VBD
VBST
BOOT
SDA
9
10
11
12
13
14
15
16
SCL
Figure 3. Pin Connections
Table 1. Pin Function Description
A functional description of each pin can be found in the FUNCTIONAL PIN DESCRIPTION section beginning on page 16.
Pin
Pin Name
Formal Name
Definition
1
FREQ
Oscillator Frequency
This switcher frequency selection pin can be adjusted by connecting external
resistor RF to the FREQ pin. The default switching frequency (FREQ pin left open or
tied to VDDI) is set to 300 kHz.
2
3
INV
Inverting Input
Output Voltage
Buck Controller Error Amplifier inverting input.
VOUT
Output voltage of the buck converter. Input pin of the switching regulator power
sequence control circuit.
4, 5
6, 7
VIN2
SW
Input Voltage 2
Switch
Buck regulator power input. Drain of the high-side power MOSFET.
Buck regulator switching node. This pin is connected to the inductor.
Analog ground of the IC, thermal heatsinking.
8, 9
GND
Ground
24, 25
10, 11
12
PGND
VBD
Power Ground
Boost Drain
Buck regulator power ground.
Drain of the internal boost regulator power MOSFET.
13
VBST
Boost Voltage
Internal boost regulator output voltage. The internal boost regulator provides a
20 mA output current to supply the drive circuits for the integrated power MOSFETs
and the external N-channel power MOSFET of the linear regulator. The voltage at
the VBST pin is 7.75V nominal.
14
15
16
17
18
19
BOOT
SDA
SCL
Bootstrap
Serial Data
Bootstrap capacitor input.
I2C bus pin. Serial data.
Serial Clock
I2C bus pin. Serial clock.
LCMP
LFB
Linear Compensation
Linear Feedback
Linear Regulator
Linear regulator compensation pin.
Linear regulator feedback pin.
LDO
Input pin of the linear regulator power sequence control circuit.
34701
Analog Integrated Circuit Device Data
Freescale Semiconductor
3
FREESCALE [ Freescale ]
