TYPICAL APPLICATION
+3.3V
Supply
Voltage
VIN1
C
IN
10uF
VBST
C
BST
10uF
10uH
L
BST
VBD
8.0V
VIN
VDDI
Internal
Supply
VBST
Power
Enable
VDDI
Bandgap
Voltage
Reference
VDDI
VDDI
Linear
Regulator
Control
I-lim
-
VDDI
VDDI
1.0 uF
VBST
LDRV
CS
LDO
7.75V
+
+
+
Reset
SysCon
INV
LFB
Vref
Q
LDO
R
S
0.022 R
Q5
Boost
Control
Vref
Vref
VLDO=3.3V
@1.0A
C
LDO
5 x 2.2 uF
Vref
+3.3V
or
VLDO
5.1k
LFB
4.7k
1.5k
EN1
EN2
Power
Sequencing
Reset
Control
POR
Timer
Voltage Margining
W-dog Timer
VLDO
Power
Down
VOUT
Pow. Seq.
UVLO
VBST
Q4
VBST
LCMP
100pF
1.5k
6.8nF
RST
to MCU
RST
RESET
Q6
RT
Rt
100k
Ct
100nF
BOOT
VIN2
(2)
VBST
Current
Limit
I
2
C
Control
SysCon
VDDI
Buck
HS
&
LS
Driver
Q1
I
2
C
Control
Thermal
Limit
C
IN
2 x 22 uF
SW
C
B
D
B
0.1uF
+3.3V
Supply
Voltage
L1
4.7 uH
SoftSt
ADDR
R
pd
10k
SDA
SCL
I
2
C
Interface
Switcher
Oscillator
300kHz
Ramp
Gen.
Buck
Control
Logic
VOUT=1.8V
+
C
O
100 uF
Q2
(2)
PGND
300k
PWM
Comp.
+
-
Error
Amp.
+
-
0.8V
To Reset
Control
(2)
INV
39k
27k
R
b
VOUT
Pow.
Seq.
Q3
VOUT
300
470pF
CLKSEL
CLKSYN
FREQ
R
F
(Optional)
(4)
GND
Figure 33. Simplified Block Diagram and Basic Application
34701
32
Analog Integrated Circuit Device Data
Freescale Semiconductor