
Analog Integrated Circuit Device Data
Freescale Semiconductor
3
34701
PIN CONNECTIONS
PIN CONNECTIONS
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 300kHz.
2
INV
Inverting Input
Buck controller error amplifier inverting input.
3
VOUT
Output Voltage
Output voltage of the buck converter. Input pin of the switching regulator power
sequence control circuit.
4, 5
VIN2
Input Voltage 2
Buck regulator power input. Drain of the high side power MOSFET.
6, 7
SW
Switch
Buck regulator switching node. This pin is connected to the inductor.
8, 9
24, 25
GND
Ground
Analog ground of the IC, thermal heatsinking.
10, 11
PGND
Power Ground
Buck regulator power ground.
12
VBD
Boost Drain
Drain of the internal boost regulator power MOSFET.
13
VBST
Boost Voltage
Internal boost regulator output voltage. The internal boost regulator provides a 20mA
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
BOOT
Bootstrap
Bootstrap capacitor input.
15
SDA
Serial Data
I
2
C bus pin. Serial data.
16
SCL
Serial Clock
I
2
C bus pin. Serial clock.
17
LCMP
Linear Compensation
Linear regulator compensation pin.
18
LFB
Linear Feedback
Linear regulator feedback pin.
19
LDO
Linear Regulator
Input pin of the linear regulator power sequence control circuit.
CLKSYN
CLKSEL
RST
1
2
EN2
EN1
ADDR
GND
GND
V
DD1
V
IN1
LDRV
CS
LDO
LFB
LCMP
RT
FREQ
INV
V
OUT
V
IN2
SW
SW
GND
GND
PGND
PGND
VBD
VBST
BOOT
SDA
SCL
V
IN2
8
9
10
11
12
13
14
15
16
3
4
5
6
7
32
31
25
24
23
22
21
20
19
18
17
30
29
28
27
26