1-1-1 Linear Regulator ICs
■Block Diagram
●SI-3010KM/SI-3012KM
●SI-3025KM/SI-3033KM/SI-3050KM/SI-3090KM/SI-3120KM
V
IN
2
1
4
5
V
OUT
VIN
VC
2
1
4
5
VO
Sense
ADJ
V
C
TSD
TSD
-
-
+
+
REF
REF
3
3
GND
GND
■Typical Connection Diagram
●SI-3025KM/SI-3033KM/SI-3050KM/
●SI-3010KM/SI-3012KM
SI-3090KM/SI-3120KM
D1*2
*2
V
D1
*1
*1
V
2
IN
VO
4
V
2
IN
O
4
R1
+
+
+
+
sense
5
V
1
C
V
1
C
ADJ
5
GND
3
GND
3
CIN
CIN
CO
CO
R2
CIN: Input capacitor (22 µF or larger)
CO: Output capacitor
R1, R2: Output voltage setting resistors
Output voltage can be set by connecting R1 and R2 as shown
above.
*1: SI-3012KM/3025KM/3033KM (22 µF or larger)
R2: 10 kΩ is recommended (24 kΩ for SI-3012KM).
It comes with a circuit configuration that uses a low ESR capacitor for the output
R1=(VO–VADJ)÷(VADJ/R2)
capacitor.
If an electrolytic capacitor is used, oscillation may occur at a low temperature.
SI-3010KM/3050KM/3090KM/3120KM (47 µF or larger)
If a low ESR capacitor is used, oscillation may occur.
*3: For SI-3010KM, insert R3 in case of setting VO to VO
≤ 1.5V.
*2: D1: Reverse bias protection diode
This diode is required for protection against reverse biasing between the input
and output.
Recommended value for R3 is 10kΩ.
(Sanken SJPL-H2 is recommended.)
This diode is not required at VO ≤ 3.3 V.
■Reference Data
Copper Laminate Area-Thermal Resistance
Copper Laminate Area-Power Dissipation
• Obtaining the junction temperature
Measure the temperatureTC at the lead part
of the GND pin with a thermocouple, etc.
Then, substitute this value in the following
formula to obtain the junction temperature.
Glass-epoxy board : 30×30mm
Glass-epoxy board : 30×30mm
100
90
80
70
60
50
40
1.5
1
Ta=25°C
40°C
60°C
Tj=PD × θj–C + TC
( θj–C = 6°C/W)
θ
0.5
0
85°C
10
100
1000
10
100
1000
Case temperature Tc
measurement point
Copper Laminate Area (mm2)
Copper Laminate Area (mm2)
ICs
18
SANKEN [ SANKEN ELECTRIC ]
