WS337L
3-TERMINAL ADJUSTABLE REGULATORS
General description
The WS337L is an adjustable 3-terminal negative voltage regulator capable of supplying 100mA over a 1.2V to 37V output range. It is
exceptionally easy to use and requires only two external resistors to set the output voltage. Furthermore, both line and load regulation are
better than standard fixed regulators, Also, the WS337L is packaged in a standard TO-92 transistor package which is easy to use.
In addition to higher performance than fixed regulators, the WS337L offers full overload protection. Included on the chip are current limit,
thermal overload protection and safe area protection. All overload protection circuitry remains fully functional even if the adjustment
terminal is disconnected.
Normally, only a single 1
μF
solid tantalum output capacitor is needed unless the device is situated more than 6 inches from the input
filter capacitors, in which case an input bypass is needed. A larger output capacitor can be added to improve transient response, the
adjustment terminal can be bypassed to achieve very high ripple rejection ratios which are difficult to achieve with standard 3-terminal
regulators.
Besides replacing fixed regulators, the WS337L is useful in a wide variety of other applications. Since the regulator is “floating” and sees
only the input-to-output differential is not exceeded.
Also, it makes an especially simple adjustable switching regulator, a programmable output regulator, or by connecting a fixed resistor
between the adjustment and output, the WS337L can be used as a precision current regulator. Supplies with electronic shutdown can be
achieved by clamping the adjustment terminal to ground that program the output to 1.2V where most loads draw little current.
The WS337L is available in a standard TO-92 transistor package and a SO-8 surface mount package. The WS337 is rated for operation
over a 0℃ to + 70℃ range.
FEATURES
♦
♦
♦
♦
♦
♦
♦
♦
Adjustable output down to 1.2V
Guaranteed 100mA output current
Line regulation typically 0.01%/V
Load regulation typically 0.1%
Current limit constant with temperature
Eliminates the need to stock many voltages
Standard 3-lead transistor package
80 dB ripple rejection
Output is short circuit protected
TO-92 WS337L
INPUT
OUTPUT
ADJ
A
!
O
I
ELECTRICAL CHARACTERISTICS
♠
1
Power dissipation
Input-Output Voltage Differential
Operating Junction
Temperature Range
Internally Limited
40v
–0℃ to +70℃
℃
℃
Storage Temperature
–55℃ to +150℃
℃
℃
Lead Temperature
Plastic Package (Soldiering 4 sec.)
260℃
℃
ESD rating to be determined.
PARAMETER
ADJUSTMENT PIN CURRENT
ADJUSTMENT PIN CURRENT CHANGE
REFERENCE VOLTAGE
LINE REGULATION
LOAD REGULATION
TEMPERATURE STABILITY
MINIMUM LOAD CURRENT
CURRENT LIMIT
RMS OUTPUT NOISE, % OF VOUT
RIPPLE REJECTION RATIO
LONG-TERM STABILITY
♠
1
♠
2
♠
3
CONDITIONS
5mA≦I
OUT
≦100mA
3V≦|V
IN
-V
OUT
|≦40V
3V≦|V
IN
-V
OUT
|≦40V,
♠
3
10mA≦I
OUT
≦100mA,P≦625MW
3V≦|V
IN
-V
OUT
|≦40V♠
2
5mA≦I
OUT
≦100mA♠
2
T
MIN
≦T
J
≦T
MAX
|V
IN
-V
OUT
|≦40V
3V≦|V
IN
-V
OUT
|≦15V
3V≦|V
IN
-V
OUT
|≦13V
|V
IN
-V
OUT
|=40V|
T
A
=25℃, 10H
Z
-f-10KH
Z
V
OUT
=-10V,F=120HZ, C
ADJ
=0
C
ADJ
=10μF
T
A
=70℃
MIN
TYP
50
0.2
MAX
100
5
-1.2
0.07
1.5
5
3.5
320
120
UNIT
μA
μA
V
%/V
%
%
mA
mA
mA
mA
%
dB
dB
%
-1.3
-1.25
0.02
0.3
0.65
3.5
2.2
200
50
0.03
65
80
0.3
100
25
66
1
: Unless otherwise specified, these specifications apply 0℃
≤
T
J
≤
70
℃
for the WS337L; V
IN
-V
OUT
= 5v and I
OUT
= 40mA. Although
power dissipation is internally limited, these specifications are applicable for power dissipation up to 625mW. I
MAX
is 100mA.
: Regulation is measured at constant junction temperature, using pulse testing with a low duty cycle. Changes in output voltage due to
heating effects are covered under the specification for thermal regulation.
: Thermal resistance of the TO-92 package is 180℃/W junction to ambient with 0.4” leads from a PC board and 160℃/W junction to
ambient with 0.125” lead length to PC board. The M package
θ
JA
is 180℃/W in still air
Tel:(852)2341 9276 Fax:(852)2797 8153
E-mail: wsccltd@hkstar.com
Wing Shing Computer Components Co., (H.K.)Ltd.
Homepage:
http://www.wingshing.com
WINGS [ WING SHING COMPUTER COMPONENTS ]
