NR885K Datasheet, PDF (1/2 Pages) Sanken electric – Surface-Mount, Current Mode Control, Synchronous Rectifier Step-down Switching Mode

1-1-3 DC/DC Converter ICs
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■Features
• Compact surface-mount package (HSOP8)
• Input voltage range (VIN): VO + 3 to 18 V
• Synchronous rectifier mode
• High efficiency: 90%
• Introduction of current mode control method
• A ceramic capacitor can be used for output
• Built-in phase correction component
• Output current: 3 A
• Reference voltage and accuracy of 0.8 V ± 2%
• Oscillation frequency: 350 kHz
• Output ON/OFF available
• Undervoltage lockout
• Soft start function
■Applications
• Power supply for LCDTV and PDP
• Power supply for DVD, BD, and STB
• On-board local power supply
• Power supply for LBP and PPC
■Absolute Maximum Ratings
Parameter
Input Voltage
Power Dissipation
Junction Temperature
Storage Temperature
Thermal Resistance (Junction to Lead (4 pins))
Thermal Resistance (Junction to Ambient Air)
Symbol
VIN
PD
Tj
Tstg
θj-c
θj-a
Ratings
20
1.69
–40 to +150
–40 to +150
40
74
Unit
V
W
°C
°C
°C/W
°C/W
Conditions
When mounted on 30 × 30 mm glass-epoxy board (with a 25 × 25 mm copper area)
When mounted on a 30 × 30 mm glass-epoxy board (with a 25 × 25 mm copper area)
■Recommended Operating Conditions
Parameter
4ZNCPM
Ratings
Unit
Input Voltage Range
7*/
4.5 or VO + 3* to 18
V
Output Current Range
*P
0
UP
3.0
A
Output Voltage Range
7P
0.8 to 14
V
Operating Temperature Range
5PQ
–40 to +85
°C
*: The minimum value of the input voltage range is 4.5 V or VO + 3 V, whichever is higher.
■Electrical Characteristics
1BSBNFUFS
Reference Voltage
Temperature Coefficient of Reference Voltage
Efficiency
Oscillation Frequency
Line Regulation
Load Regulation
Overcurrent Protection Starting Current
Quiescent Circuit Current 1
Quiescent Circuit Current 2
SS Pin
Outflow Current at Low Voltage
Open Voltage
EN Pin
Inflow Current
On Threshold Voltage
Maximum ON Duty
Minimum ON Time
Thermal Protection Start Temperature
Thermal Protection Return Hysteresis
4ZNCPM
73&'
᷎73&'᷎5
η
GP
7-*/&
7-PBE
*T
**/
**/ PGG
*&/44
744)
*&/
7$&)
%."9
%.*/
54%
54%@IZT
min.
0.784
280
3.1
6
0.7
151
Ratings
typ.
0.800
±0.05
90
350
50
50
6
10
3.0
50
1.4
90
150
165
20
max.
0.816
420
6.0
10
14
100
2.1
*: Pin 8 is the SS pin. Soft start at power on can be performed with a capacitor connected to this pin.
The SS pin is pulled up to the power supply in the IC, so applying the external voltage is prohibited.
(Ta=25°C, VIN=12V, VO=3.3V, and Io=1A, unless otherwise specified)
Unit
V
mV/ˆ
%
kHz
mV
mV
A
mA
µA
µA
V
µA
V
%
nsec
ˆ
ˆ
$POEJUJPOT
5B–ˆ
UP
ˆ
7*/7
UP
7
*P"
UP
"
7&/7
*P"
7&/7
7447
7&/7
NR885K
8 SS
C9
ɹ4PGU
TUBSU
20 ICs