New Product Bulletin
4ch System Power Supply IC for CCD Cameras
Energy
Saving
BD8676KN
Monolithic CCD camera power supply
features 80%+ efficiency even during
4ch driving
Product outline
Two power supplies are built in for system ICs in addition to the positive/negative supplies required for CCD
cameras, resulting in 4ch drive capability on a single chip. Built-in switching and LDO regulators result in an
efficiency of greater than 80% during full-drive (all-channel) operation, reducing heat generation
considerably. In addition, the integrated startup sequence control circuit makes complicated control
unnecessary, simplifying design while reducing costs.
Over 80% efficiency (During all-channel driving)
Power supplies for the CCD camera (2) as well as for the image processor
IC input / output and core (2) are built into a single chip. In addition, a FET,
phase compensation, and feedback resistor are integrated at each channel,
reducing the number of parts required while contributing to greater
miniaturization.
Block Diagram
V IN
4.5V to 9V
Video
Driver
For I/O
CTL1
CTL2
CTL3
CTL4
Step-down Switching
1ch
Regulator 1
Sequence
Control
3.3V
Image
Processor
For Core
1.2V
150mA
Inverter
Charge Pump
10
100
Load Current (mA)
15V
LDO
15mA
3ch
Integrating a startup sequence for both
positive and negative power supplies
prevents damage to the CCD sensor
while maximizing performance. For
example, the BD8676KN controls the
startup timing of all 4 channels,
ensuring
safe
operation
while
eliminating the need for complicated
1000
-5.5V
I
n
t
e
r
f
a
c
e
15V
3.3V
1.2V
C
C
D
S
e
n
s
o
r
C
C
D
S
e
n
s
o
r
( )
Protection
Circuits
80%+
(4ch operation)
3.3V System
All Ch Drive
( )
OSC
Step-up
Switching
Regulator
90
80
70
60
50
40
30
20
10
0
Built-in startup sequence control
150mA
Step-down Switching 2ch
Regulator 2
Output Conversion Efficiency
100
Output Voltage
BD8676KN
CCD sensors typically feature much
greater power consumption than CMOS
sensors. Utilizing a combination of
switching and LDOregulators has
allowed ROHM to increase efficiency
significantly, to more than 80% during
all-channel driving. This results in
reduced heat generation and energy
consumption while contributing to
increased miniaturization.
Efficiency (%)
All 4 required channels on a single chip
I P
mr
ao
gc
e e
s
s
o
r
+
Time
-5.5V
-
-5mA
LDO
4ch
Phase compensation and feedback resistor built into each channel
CCD
Sensor
Integrated high accuracy reset circuit (±1%)
Equipped with multiple protection circuits
• Abnormal output voltage detection
• Thermal shutdown
Specifications
Part No.
BD8676KN
Input Voltage (V)
4.5 to 9.0
(18V max.)
Output Current
3.3V : 150mA
1.2V : 150mA
15V : 15mA
-5.5V : -5mA
Switching Frequency
500kHz to 1.2MHz
(Adjustable via external resistor)
• Off latch function
• Startup fault detection Output Voltage Accuracy (%) Operating Temp. Range (˚C)
±2
The content specified in this document is correct as of 7th July, 2009.
Catalog No. 52F6150E 2009.07 ROHM ©
-40 to 85
Package
VQFN36