34701_07 Datasheet, PDF (34/38 Pages) Freescale Semiconductor, Inc – 1.5 A Switch-Mode Power Supply with Linear Regulator

TYPICAL APPLICATIONS
+3.3V
Supply
Voltage
VIN1
VIN
C_IN
10uF
VBST 8.0V
C_BST
10uF
7.75V
10uH
L_BST VBD _Q5
+3.3V
or
VLDO
5.1k
RST
to MCU
EN1
EN2
R^RE^SS^TET
Q6
RT
Boost
Control
Reset
Control
POR
Timer
Rt
100k
Ct
100nF
I²C
Control
ADDR
VBST
Power
Enable
Vref
VDDI
Vref ^Bandgap
Voltage
Vref
Reference
VDDI
Internal
Supply
VDDI
VBST
VDDI
VDDI _Linear
Regulator
Control
Vref
I-lim
Reset
SysCon
INV
LFB
Thermal
Limit
Power
Sequencing
VLDO Pow. Seq.
Power
Down _UVLO
Voltage Margining
VOUT
W-dog Timer
VBST
Current
Limit
I²C
Control
VDDI
Buck
HS
SysCon
SoftSt
Buck
Control
Logic
&
LS
Driver
VDDI
1.0 uF
LDRV
CS
LDO
Q_LDO
R_S
0.022 R
VLDO=3.3V
@1.0A
LFB
4.7k
1.5k
Q4 ^{LCMP 1.5k}
100pF
VBST
6.8nF
C_LDO
5 x 2.2 uF
BOOT
VBST
VIN2
(2)
Q1
C_IN
2 x 22 uF
SW
(2)
Q2
+3.3V
Supply
Voltage
D_B
C_B 0.1uF
L1
4.7 uH
R_pd
10k
SDA
SCL
I²C
Interface
Switcher
Oscillator
300kHz
Ramp
Gen.
PWM
Comp.
+
-
Error
Amp.
To Reset
+ ^{0.8V Control}
-
PGND
(2)
INV
VOUT
Pow.
Seq.
Q3 ^VOUT
300k
27k Rb
39k
300
470pF
CLKSEL
CLKSYN
FREQ
R_F
(Optional)
(4)
GND
VOUT=1.8V
+
C_O
100 uF
Figure 33. Simplified Block Diagram and Basic Application
34701
34
Analog Integrated Circuit Device Data
Freescale Semiconductor