廬
PWS750
Isolated, Unregulated
DC/DC CONVERTER COMPONENTS
FEATURES
q
100% TESTED FOR HIGH-VOLTAGE
BREAKDOWN
q
COMPACT-SURFACE MOUNT
q
MULTICHANNEL OPERATION
q
5V OR 15V INPUT OPTIONS
q
FLEXIBLE USE WITH PWS740/PWS745
COMPONENTS
APPLICATIONS
q
INDUSTRIAL PROCESS CONTROL
EQUIPMENT
q
GROUND-LOOP ELIMINATION
q
PC-BASED DATA ACQUISITION
q
VENDING MACHINES
The PWS750-2U and PWS750-4U are split-bobbin
wound isolation transformers using a ferrite core.
They are encapsulated in plastic packages, allowing a
high isolation voltage rating.
The PWS750-3U is a high-speed monolithic diode
bridge in a plastic 8-pin SO package.
One PWS750-1U can be used to drive up to four
channels (15V nominal operation). One PWS750-2U
and PWS750-3U and two 2N7002 (surface mount) or
2N7008 (TO-92) MOSFETs made by Siliconix are
used per isolated channel. When a PWS750-4U is
used as the transformer (5V input), then two TN0604s
made by Supertex must be used, due to the higher
currents of the primary (lower RDS on) and the lower
V
GS
threshold. With 5V operation only one channel
can be directly driven by the PWS750-1U (a simple
FET booster circuit can be used for multichannel
operation; see Figure 3).
2N7002
(2)
or
2N7008
D
G
S
6
0.3碌F
Soft
Start
14
TTL
IN
Typical Connection for
Internal Oscillator Operation
DESCRIPTION
The PWS750 consists of three building blocks for
building a low cost DC/DC converter. With them you
can optimize DC/DC converter PC board layout or
build a multichannel isolated DC/DC converter. All
parts are surface mount, requiring minimal space to
build the converter. The modular design minimizes the
cost of isolated power.
The PWS750-1U is a high-frequency (800kHz nomi-
nal) driver that can drive N-channel MOSFETs up to
the size of a 1.3A 2N7010. The recommended
MOSFET for individual transformer drivers is the
2N7008. The PWS750-1U is supplied in a 16-pin
double-wide SO package.
PWS750 SINGLE-CHANNEL CONNECTION
10碌H
(1)
+V
+V
IN
7
PWS750-1U
Reference
Comparator
1
R
S
Driver
Differential
Amplifier
Oscillator
16
T
10
Enable
10鈩?/div>
(3)
PWS750-2U
5
4
3
3
6
1
PWS750-3U
4
10鈩?/div>
(3)
T
V
D
3
11
0.3碌F
Input
Gnd
D
G
S
7
2
12
TTL
OUT
Output
(2)
2N7002
Ground
or
2N7008
Duplicate for multichannel
operation with PWS750-2U.
0.3碌F
0.3碌F
10鈩?/div>
鈥揤
O
(1)
10鈩?/div>
+V
O
(1)
NOTES: (1) User option. (2) Use TN0604 for 5V to
鹵15V
operation. (3) Multichannel Operation.
International Airport Industrial Park 鈥?Mailing Address: PO Box 11400, Tucson, AZ 85734 鈥?Street Address: 6730 S. Tucson Blvd., Tucson, AZ 85706 鈥?Tel: (520) 746-1111 鈥?Twx: 910-952-1111
Internet: http://www.burr-brown.com/ 鈥?FAXLine: (800) 548-6133 (US/Canada Only) 鈥?Cable: BBRCORP 鈥?Telex: 066-6491 鈥?FAX: (520) 889-1510 鈥?Immediate Product Info: (800) 548-6132
廬
漏
1988 Burr-Brown Corporation
PDS-838F
1
Printed in U.S.A.
PWS750
April, 1997
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