NTE956
Integrated Circuit
3–Terminal Adjustable Positive
Voltage Regulator
Description:
The NTE956 is an adjustable 3–terminal positive voltage regulator in a TO220 type package capable
of supplying in excess of 1.5A over a 1.2V to 37V output range. This device is exceptionally easy to
use and both line and load regulation are better than standard fixed regulators.
In addition to higher performance than fixed regulators, the NTE956 offers full overload protection
available only in IC’ s. 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, no capacitors are needed unless the device is situated far from the input filter capacitors
in which case an input bypass is needed. An optional output capacitor can be added to improve tran-
sient 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 NTE956 is useful in a wide variety of other applications. Since
the regulator is “floating” and sees only the input–to–output differential voltage, supplies of several
hundred volts can be regulated as long as the maximum 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 NTE956 can be used as a
precision current regulator. Supplies with electronic shutdown can be achieved by clamping the ad-
justment terminal to GND which programs the output to 1.2V where most loads draw little current.
Features:
DAdjustable Output Down to 1.2V
DGuaranteed 1.5A Output Current
DLine Regulation Typically 0.01%/V
DLoad Regulation Typically 0.1%
DCurrent Limit Constant with Temperature
D100% Electrical Burn–In
DEliminates the Need to Stock Many Voltages
D80dB Ripple Rejection
Absolute Maximum Ratings:
Power Dissipation, PDInternally Limited. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Input–Output Voltage Differential, VI–VO40V. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating Junction Temperature Range, TJ0° to +125°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Storage Temperature Range, Tstg –65° to +150°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Typical Thermal Resistance, Junction–to–Case, RthJC 4°C/W. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lead Temperature (During Soldering, 10sec), TL+300°C. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Electrical Characteristics: (0° ≤ TJ ≤ +125°C, VIN–VOUT = 5V, IO = 500mA, IMAX = 1.5A, Note 1
unless otherwise specified)
Parameter Symbol Test Conditions Min Typ Max Unit
Line Regulation Regline TA = + 25°C, 3V ≤ (VIN–VOUT) ≤ 40V, Note 2 –0.01 0.04 %/V
3V ≤ (VIN–VOUT) ≤ 40V –0.02 0.07 %/V
Load Regulation Regload TA = + 25°C,
≤ ≤
VOUT ≤ 5V –5 25 mV
10mA
≤
IO
≤
1MAX,
Note 2 VOUT ≥ 5V –0.1 0.5 %
10mA ≤ IO ≤ 1MAX, Note 2 VOUT ≤ 5V –20 70 mV
VOUT ≥ 5V –0.3 1.5 %
Thermal Regulation TA = +25°C, 20ms Pulse –0.04 0.07 %/W
Adjustment Pin Current IAdj –50 100 µA
Adjustment Pin Current
Change ∆IAdj 10mA ≤ IL ≤ IMAX, 2.5 V ≤ (VIN–VOUT) ≤ 40V –0.2 5.0 µA
Reference Voltage Vref 3V ≤ (VIN–VOUT) ≤ 40V, 10mA ≤ IO ≤ 1MAX,
P ≤ PMAX 1.20 1.25 1.30 V
Temperature Stability TS0° ≤ TJ ≤ +125°C–1–%
Minimum Load Current ILmin (VIN–VOUT) ≤ 40V –3.5 10 mA
Maximum Output Current Imax VIN–VOUT ≤ 15V 1.5 2.2 –A
Limit VIN–VOUT = 40V –0.4 –A
RMS Output Noise,
% of VOUT N TA = +2 5°C, 10Hz ≤ f ≤ 10kHz –0.003 –%
Ripple Rejection Ratio RR VOUT = 10V, f = 120Hz –65 –dB
CADJ = 10µF 66 80 –dB
Long Term Stability S TA = +125°C, 1000 Hours –0.3 1.0 %
Note 1. Although power dissipation is internally limited, these specifications are applicable for power
dissipations of 20W.
Note 2. Regulation is measured at constant junction temperature, using pulse testing with a low duty
cycle. Changes in output voltage due to heating ef fects are covered under the specification
for thermal regulation.
.500
(12.7)
Min
.420 (10.67)
Max
.500
(12.7)
Max
.250
(6.35)
Max
.147 (3.75)
Dia Max
.070 (1.78)
Max
.100 (2.54)
Adj
VOUT/Tab
VIN
.110 (2.79)
