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Zetex Semiconductors |
2.85 TO 12 VOLT FIXED POSITIVE
LOCAL VOLTAGE REGULATOR
ISSUE 3 - DECEMBER 2001
ZR78L
SERIES
DEVICE DESCRIPTION
The ZR78L Series three terminal fixed positive
voltage regulators feature internal circuit
current limit and thermal shutdown making
the devices difficult to destroy. The circuit
design allows creation of any custom voltage
in the range 2.85 to 12 volts. The devices are
available in a small outline surface mount
package, ideal for applications where space
saving is important, as well as through hole
TO92 style packaging. The devices are suited
to local voltage regulation applications, where
problems could be encountered with
distributed single source regulation, as well as
more general voltage regulation applications.
The ZR78L Series show performance
characteristics superior to other local voltage
regulators. The initial output voltage is
maintained to within 2.5% with a quiescent
current of typically 350µA. Output voltage
change, with input voltage and load current, is
much lower than competitive devices. The
ZR78L devices are completely stable with no
external components. The device will shut
down under thermal overload conditions but
as the device cools, regulation will restart.
FEATURES
• Small outline SOT223 package
• SO8 package (3.3V and 5.0V)
• TO92 package
• 2.85 to 12 Volt
• Output current up to 200mA
• Tight initial tolerance
• Low quiescent current
• -55 to 125°C temperature range
• No external components
• Internal thermal shutdown
• Internal short circuit current limit
VOLTAGE RANGE
ZR78L028 2.85V
ZR78L03 3.0V
ZR78L033 3.3V
ZR78L04 4.0V
ZR78L048 4.85V
ZR78L05 5.0V
ZR78L052 5.2V
ZR78L057 5.7V
ZR78L06 6.0V
ZR78L07 7.0V
ZR78L08 8.0V
ZR78L085 8.5V
ZR78L09 9.0V
ZR78L10 10.0V
ZR78L12 12.0V
4-200
ZR78L
SERIES
ABSOLUTE MAXIMUM RATING
Input voltage
20V
Output Current(Io) 200mA
Operating Temperature -55 to 125°C
Storage Temperature -65 to 150°C
Power Dissipation (Tamb=25°C)
SOT223
2W(Note 3)
TO92
600mW
S08 780mW(Note 3)
ELECTRICAL CHARACTERISTICS:
Notes:
1. The maximum operating input voltage and
output current of the device will be governed by
the maximum power dissipation of the selected
package. Maximum package power dissipation is
specified at 25 °C and must be linearly derated to
zero at Tamb=125°C.
2. The following data represents pulse test
conditions with junction temperatures as
indicated at the initiation of the test. Continuous
operation of the devices with the stated conditions
might exceed the power dissipation limits of the
chosen package.
3. Maximum power dissipation, for the SOT223
and SO8 packages, is calculated assuming that the
device is mounted on a PCB measuring 2 inches
square.
4. The shut down feature of the device operates if
its temperature exceeds its design limit as might
occur during external faults, short circuits etc. If the
regulator is supplied from an inductive source
then a large voltage transient, on the regulator
input, can result should the shut down circuit
operate. It is advised that a capacitor (1µF or
greater) should be applied across the regulator
input to ensure that the maximum voltage rating
of the device is not exceeded under shutdown
conditions.
ZR78L028 TEST CONDITIONS (Unless otherwise stated):Tj=25°C, IO=100mA, Vin=6.85V
SYMBOL PARAMETER
CONDITIONS MIN. TYP. MAX. UNITS
VO Output Voltage
2.78
IO=1 to 200mA τ 2.736
2.85
2.92
2.964
V
V
Vin=4.85 to 20V 2.736
IO=1 to 100mA τ
∆VO Line Regulation
Vin=4.85 to 20V
∆VO Load Regulation
IO=1 to 200mA
IO=1 to 100mA
lq Quiescent Current
τ
∆lq Quiescent Current Change IO=1 to 200mA
Vin=4.85 to 20V
Vn Output Noise Voltage
f=10Hz to 10kHz
∆Vin /∆VO Ripple Rejection
Vin=5.85 to 18V
f=120Hz
48
10
5
2
350
75
62
2.964 V
40 mV
25 mV
mV
600 µA
100 µA
100 µA
µV rms
dB
Vin Input Voltage Required To
Maintain Regulation
4.85 4.55
V
∆VO /∆T Average Temperature
IO=5.0mA τ
Coefficient of VO
0.1 mV/°C
τ=Tj=-55 to 125°C
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