SR087SG-G Supertex, SR087SG-G Datasheet - Page 6

• Manufacturer Part Number: SR087SG-G
• Description: Switching Converters, Regulators & Controllers 5.0V Adjust Off-Line Switching Regulator
• Manufacturer: Supertex

Specifications of SR087SG-G

• Output Voltage: 50 V
• Output Current: 100 mA
• Output Power: 1 W
• Input Voltage: 120 V to 230 V
• Operating Temperature Range: - 40 C to + 125 C
• Mounting Style: SMD/SMT
• Package / Case: SOIC-8
• Number Of Outputs: 2
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

V
load is calculated as follows:
UPS
The SR087 will not operate from uninterruptable power
supplies having a square wave output. This type of output is
usually referred to as ‘modified sine wave’.
Transient Protection
The transient protector must be located before the bridge
rectifier. The reason for this is to minimize capacitance to
allow the rectified AC to fall below V
Additional Transient Protection
Pin Description
270VAC
50/60Hz
OUT
90 to
, it also includes the current drawn from V
VREG
Name
VOUT
GATE
GND
VGD
VIN
EN
FB
I
P
LOAD
LOAD
Supertex inc.
= I
1.0A
= V
275V
50A
OUT
OUT
+ I
Wire Wound
10Ω, 3.0W
Pin
(I
1
2
3
4
5
6
7
8
REG
OUT
+ I
REG
1.0µF
240VAC
X2
Description
Rectified AC input voltage
Active low enable input
Circuit ground
Note: circuit ground will be at the AC line potential
Regulated output voltage, fixed 5.0V
Feedback input
Output voltage (9.0 - 50V adj.)
Gate drive supply (referenced to V
Drives external IGBT pass transistor
)
●
OUT
1235 Bordeaux Drive, Sunnyvale, CA 94089
.
200kΩ
200kΩ
REG
1.0kV
1.0A
Enable
(I
REG
). Total
510kΩ
510kΩ
STGD5NB120SZ
VIN
EN
GATE
6
Since there is no capacitor to absorb AC line transients,
complete transient protection must be provided by the TVS
or MOV device. Since the recommended IGBT is rated at
1.2kV and the SR087 never sees the full input voltage, the
bridge rectifier becomes the limiting element when selecting
an MOV. If using a 1.0kV bridge, an MOV having a clamping
voltage of < 1.0kV is recommended.
An RC network on the AC line, as shown in the circuit below,
affords additional protection from line transients, as well as
reducing conducted EMI. It does, however, reduce power
supply efficiency.
OUT
SR087
)
GND
VGD
100nF
●
VOUT
VREG
Tel: [phone]
FB
5.0V
@60mA
1.0µF
100nF
●
www.supertex.com
470µF
R
10.0k
R
2
1
= R
V
9.0 - 50VDC
@ 100mA - I
Ω
OUT
2
SR087
1.25V
V
OUT
- 1
REG