PIN CONNECTIONS
PIN CONNECTIONS
56 55 54 53 52 51 50 49 48 47 46 45 44 43
56 55 54 53 52 51 50 49 48 47 46 45 44 43
1
1
42
41
40
39
38
37
36
35
34
33
32
31
30
29
BT5U
BT4D
PVIN4
SW4D
VOUT4
SW4U
BT4U
FB4
42
41
40
39
38
37
36
35
34
33
32
31
30
29
BT5U
BT4D
PVIN4
SW4D
VOUT4
SW4U
BT4U
FB4
BT2U
ONOFF
LION
BT2U
ONOFF
LION
VDDI
VIN
2
2
3
57
57
3
4
4
VDDI
5
5
VIN
6
6
AGND
VOUT6
SW6
AGND
PGND5
Exposed Pad
PGND
Exposed Pad
PGND
7
7
8
8
PGND4
NC4
BT6
COMP4
BT3
COMP4
BT3
9
9
10
11
12
13
14
10
11
12
13
14
FB6
AGND3
PGND2
NC3
PVIN3
SW3
PVIN3
SW3
VOUT7
DRV7
FB7
VOUT3
FB3
VOUT3
FB3
AGND1
NC2
VREF7
15 16 17 18 19 20 21 22 23 24 25 26 27 28
15 16 17 18 19 20 21 22 23 24 25 26 27 28
34704A
34704B
Figure 3. 34704 Pin Connections
Table 2. 34704 Pin Definitions
A functional description of each pin can be found in the Functional Pin Description section beginning on page 17.
Pin Number Device Pin Name Pin Function
Formal Name
Definition
1
2
3
A/B
A/B
A/B
BT5U
BT4D
PVIN4
REG5 Boost Stage
Connect a 1.0 μF capacitor between this pin and SW5U pin to
Passive
Passive
Power
bootstrap capacitor input enhance the gate of the Switch Power MOSFET.
pin
REG4 Buck Stage
Connect a 0.01 μF capacitor between this pin and SW4D pin to
bootstrap capacitor input enhance the gate of the Switch Power MOSFET.
pin
REG4 power supply input This is the connection to the drain of the high side switch FET.
voltage
Input decoupling /filtering is required for proper REG4 operation.
Use a 10uf decoupling capacitor for better performance.
4
5
6
7
A/B
A/B
A/B
A/B
SW4D
VOUT4
SW4U
BT4U
REG4 Buck Stage
switching node
The inductor is connected between this pin and the SW4U pin.
Input/Output
Output
REG4 regulated output
voltage pin
Connect this pin to the load and to the output filter as close to
the pin as possible.
REG4 Boost Stage
switching node
The inductor is connected between this pin and the SW4D pin.
Input/Output
Passive
REG4 Boost Stage
Connect a 0.01 μF capacitor between this pin and SW4U pin to
bootstrap capacitor input enhance the gate of the Switch Power MOSFET.
pin
8
A/B
FB4
REG4 voltage feedback
input for voltage
regulation/programming
Connect the feedback resistor divider to this pin.
REG4 compensation network connection.
Input
9
A/B
A/B
COMP4
BT3
REG4 compensation
network connection
Passive
Passive
10
REG3 bootstrap capacitor Connect a 0.01 μF capacitor between this pin and SW3 pin to
input pin enhance the gate of the Switch Power MOSFET.
34704
Analog Integrated Circuit Device Data
Freescale Semiconductor
4
FREESCALE [ Freescale ]
