I Features

•Compact full-mold package (equivalent to TO220)•Output current: 1.5A

•Low dropout voltage: V DIF ≤1V (at I O =1.5A)•

Variable output voltage (rise only)May be used for remote sensing

•Output ON/OFF control terminal is compatible with LS-TTL.(It may be directly driven by LS-TTL or standard CMOS logic.)

•Built-in foldback overcurrent (SI-3033C: Drooping type overcurrent),overvoltage, thermal protection circuits

I Applications

•For stabilization of the secondary stage of switching power supplies •Electronic equipment

*1:"A" may be indicated to the right of the Sanken logo.

*2:V IN(max) and I O(max) are restricted by the relation P D(max)=(V IN-V O)•I O=18(W).

*3:Refer to the dropout voltage.(Refer to Setting DC Input Voltage on page 7.)

*4:I S1 is specified at –5(%) drop point of output voltage V O on the condition that V IN=V O+3V, I O=1A.

*5:Output is ON even when output control terminal V C is open. Each input level is equivalent to LS-TTL. Therefore, it may be directly driven by an LS-TTL circuit.

*6:A foldback type overcurrent protection circuit is built into the I C regulator (excluding SI-3033C). Therefore, avoid using it for the following applica-tions as it may cause starting errors:

(1) Constant current load (2) Plus/minus power (3) Series power (4) V O adjustment by raising ground voltage

*1:"A" may be indicated to the right of the Sanken logo.

*2:V IN(max) and I O(max) are restricted by the relation P D(max)=(V IN-V O)•I O=18(W).

*3:Refer to the dropout voltage.(Refer to Setting DC Input Voltage on page 7.)

*4: I S1 is specified at –5(%) drop point of output voltage V O on the condition that V IN=V O+3V, I O=1A.

*5:Output is ON even when output control terminal V C is open. Each input level is equivalent to LS-TTL. Therefore, it may be directly driven by an LS-TTL circuit.

*6:A foldback type overcurrent protection circuit is built into the I C regulator. Therefore, avoid using it for the following applications as it may cause starting errors:

(1) Constant current load (2) Plus/minus power (3) Series power (4) V O adjustment by raising ground voltage

a D

1. Variable output voltage with a single external resistor

The output voltage may be increased by inserting resistor R EX between terminals No.4 (sensing terminal) and No.3 (output terminal). The cur-rent I REX flowing into terminal No.4 is 1mA (typ.)(SI-3033C:0.43mA (typ.)),therefore the adjusted output voltage V OUT is:

V O =V 04+I REX •R EX *V 04: output voltage of SI-3000C series

However, the internal resistor (between terminals No. 4 and No.1) is a semiconductor resistor, which has approximately thermal characteris-tics of +0.2%/°C.

It is important to keep the thermal characteristics in mind when adjust-ing the output voltage.

2. Variable output voltage with two external resistors

The output voltage may be increased by inserting resistors R EX1 be-tween terminals No.4 (sensing terminal) and No.3 (output terminal) and R EX2 between terminals No.4 and No.1 (ground terminal).

The current I 4IN flowing into terminal No.4 is 1mA (typ.)(SI-3033C:0.43mA (typ.)) so the thermal characteristics may be improved com-pared to the method shown in 1 by setting the external current I REX1 at approximately 5 times the value of I 4IN (stability coefficient S=5).The adjusted output voltage V OUT in this case is:

V O =V 04+R EX1•I REX1I REX1=S •I 4IN

The value of the external resistors may be obtained as follows:

R EX1= V O -V 04 R EX2=

V 04

S •I 4IN , (S-1)•I 4IN

*V 04: Output voltage of SI-3000C series

S: Stability coefficient of I 4IN (may be set to any value)

Note: In the SI-3000C series, the output voltage increase can be ad-justed as mentioned above. However, when the rise is set to ap-proximately 10V compared to output voltage V 04, the necessary

output current may not be obtained due to the S.O.A. protection

circuit in the SI-3000C series.

5

O u t p u t V o l t a g e V O (V )

External Resistor R EX (k Ω)

External Resistor R EX1 (k Ω)

O u t p u t V o l t a g e V O (V )

External Variable Output Voltage Circuit

41下载本文