R1212D Datasheet, PDF (10/41 Pages) RICOH electronics devices division – STEP-UP DC/DC CONTOLLER

R1212D
TYPICAL APPLICATIONS AND TECHNICAL NOTES
Inductor
Diode
VOUT
C1
C2
C6
R5
VIN
DELAY
EXT
VFB
R3
NMOS
C4
GND AMPOUT
VREFOUT
DTC
C5 R4
R6
C7
R1
C3
R2
Inductor
NMOS
Diode
C1
C2
C3
C4
C5
LDR655312T-100(TDK) [R1212DxxxA]
LDR655312T-4R7(TDK) [R1212DxxxB]
LDR655312T-220(TDK) [R1212DxxxC]
CPH6415 (Sanyo)
CRS02 (Toshiba)
2.2µF
1µF
1.5µF
1000pF[R1212DxxxA]
680pF[R1212DxxxB]
1500pF[R1212DxxxC]
1000pF[R1212DxxxA]
680pF[R1212DxxxB]
1500pF[R1212DxxxC]
C6
C7
Set V
R1
R2
R3
R4
R5
R6
0.1µF
0.1µF
5V
120kΩ
30kΩ
10V
180kΩ
20kΩ
1kΩ
4.7kΩ
240kΩ
300kΩ
15V
140kΩ
10kΩ
Use a 1µF or more capacitance value of bypass capacitor between VIN pin and GND, C1 as shown in the
typical application above. Connect the capacitor as short as possible to the IC.
• In terms of the capacitor for setting delay time of the latch protection, C2 is shown in typical application above.
Latch delay time depends on this C2 value. Refer to the Latch Protection Operation Timing Chart.
• Connect a 1µF or more value of capacitor between VOUT and GND, C3 as shown in typical application above.
(Recommended value is from 10µF to 22µF.) If the operation of the composed DC/DC converter may be
unstable, use a tantalum type capacitor instead of ceramic type
• Connect a capacitor between VREFOUT and GND, C6 as shown in typical application of the previous page.
The capacitance value of C6 is between 0.1µF and 1.0µF.
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