LP2950
Micropower Voltage
Regulators
The LP2950 and LP2951 are micropower voltage regulators that are
specifically designed to maintain proper regulation with an extremely
low input–to–output voltage differential. These devices feature a very
low quiescent bias current of 75
µA
and are capable of supplying
output currents in excess of 100 mA. Internal current and thermal
limiting protection is provided.
The LP2951 has three additional features. The first is the Error
Output that can be used to signal external circuitry of an out of
regulation condition, or as a microprocessor power–on reset. The
second feature allows the output voltage to be preset to 5.0 V, 3.3 V or
3.0 V output (depending on the version) or programmed from 1.25 V
to 29 V. It consists of a pinned out resistor divider along with direct
access to the Error Amplifier feedback input. The third feature is a
Shutdown input that allows a logic level signal to turn–off or turn–on
the regulator output.
Due to the low input–to–output voltage differential and bias current
specifications, these devices are ideally suited for battery powered
computer, consumer, and industrial equipment where an extension of
useful battery life is desirable. The LP2950 is available in the three
pin case 29 and DPAK packages, and the LP2951 is available in the
eight pin dual–in–line, SO–8 and Micro–8 surface mount packages.
The ‘A’ suffix devices feature an initial output voltage tolerance
±
0.5%.
LP2950 and LP2951 Features:
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TO–92
Z SUFFIX
CASE 29
1
2
3
Pin: 1. Output
2. Ground
3. Input
DPAK
DT SUFFIX
CASE 369A
1
3
PIN CONNECTIONS
Pin: 1. Input
2. Ground
3. Output
1
2
3
(Top View)
Heatsink surface (shown as terminal 4 in
case outline drawing) is connected to Pin 2.
SO–8
D SUFFIX
CASE 751
•
Low Quiescent Bias Current of 75
µA
•
Low Input–to–Output Voltage Differential of 50 mV at 100
µA
and
•
•
•
•
380 mV at 100 mA
5.0 V, 3.3 V or 3.0 V
±
0.5% Allows Use as a Regulator or Reference
Extremely Tight Line and Load Regulation
Requires Only a 1.0
µF
Output Capacitor for Stability
Internal Current and Thermal Limiting
8
1
LP2951 Additional Features:
N SUFFIX
CASE 626
8
1
•
Error Output Signals an Out of Regulation Condition
•
Output Programmable from 1.25 V to 29 V
•
Logic Level Shutdown Input
(See Following Page for Device Information.)
Micro–8
DM SUFFIX
CASE 846A
8
1
PIN CONNECTIONS
Output 1
Sense 2
Shutdown 3
Gnd 4
(Top View)
8
7
6
5
Input
Feedback
VO Tap
Error Output
ORDERING INFORMATION
See detailed ordering and shipping information in the package
dimensions section on page 13 of this data sheet.
©
Semiconductor Components Industries, LLC, 1999
1
October, 1999 – Rev. 5
Publication Order Number:
LP2950/D
LP2950
DEVICE INFORMATION
Output Voltage
Package
TO–92
Suffix Z
DPAK
Suffix DT
SO–8
Suffix D
Micro–8
Suffix DM
DIP–8
Suffix N
3.0V
LP2950CZ–3.0
LP2950ACZ–3.0
LP2950CDT–3.0
LP2950ACDT–3.0
LP2951CD–3.0
LP2951ACD–3.0
LP2951CDM–3.0
LP2951ACDM–3.0
LP2951CN–3.0
LP2951ACN–3.0
3.3V
LP2950CZ–3.3
LP2950ACZ–3.3
LP2950CDT–3.3
LP2950ACDT–3.3
LP2951CD–3.3
LP2951ACD–3.3
LP2951CDM–3.3
LP2951ACDM–3.3
LP2951CN–3.3
LP2951ACN–3.3
5.0V
LP2950CZ–5.0
LP2950ACZ–5.0
LP2950CDT–5.0
LP2950ACDT–5.0
LP2951CD
LP2951ACD
LP2951CDM
LP2951ACDM
LP2951CN
LP2951ACN
Adjustable
Not
Available
Not
Available
LP2951CD
LP2951ACD
LP2951CDM
LP2951ACDM
LP2951CN
LP2951ACN
Operating Junction
Temperature Range
TJ = –40° to +125°C
TJ = –40° to +125°C
TJ = –40° to +125°C
TJ = –40° to +125°C
TJ = –40° to +125°C
LP2950Cx–xx / LP2951Cxx–xx
LP2950ACx–xx / LP2951ACxx–xx
1% Output Voltage Precision at TJ = 25°C
0.5% Output Voltage Precision at TJ = 25°C
Representative Block Diagrams
Input
Battery or
Unregulated DC
3
182 k
Error Amplifier
1.23 V
Reference
Gnd
Battery or
Unregulated DC
Input
8
2
Output
1
Sense
182 k
2
5.0 V/100 mA
1.0
µF
VO Tap
6
60 k
7
Error
Amplifier
60 k
50 k
75 mV/
60 mV
Feedback
330 k
Output
1
5.0 V/100 mA
1.0
µF
60 k
LP2950CZ–5.0
Shutdown
From
3
CMOS/TTL
Error
Output
To CMOS/TTL
5
1.23 V
Reference
Gnd
4
Error Detection
Comparator
LP2951CD or CN
This device contains 34 active transistors.
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2
LP2950
MAXIMUM RATINGS
(TA = 25°C, unless otherwise noted.)
ÁÁÁ
Á
Á
Á
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
Á
Á
ÁÁÁ
Á
Á
Á
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
Á
Á
Input Voltage
VCC
PD
30
Vdc
W
Power Dissipation and Thermal Characteristics
Maximum Power Dissipation
Case 751(SO–8) D Suffix
Thermal Resistance, Junction–to–Ambient
Thermal Resistance, Junction–to–Case
Case 369A (DPAK) DT Suffix [Note 1]
Thermal Resistance, Junction–to–Ambient
Thermal Resistance, Junction–to–Case
Case 29 (TO–226AA/TO–92) Z Suffix
Thermal Resistance, Junction–to–Ambient
Thermal Resistance, Junction–to–Case
Case 626 N Suffix
Thermal Resistance, Junction–to–Ambient
Case 846A (Micro–8) DM Suffix
Thermal Resistance, Junction–to–Ambient
Feedback Input Voltage
Internally Limited
180
45
92
6.0
160
83
105
240
–1.5 to +30
–0.3 to +30
–0.3 to +30
R
θJA
R
θJC
R
θJA
R
θJC
R
θJA
R
θJC
R
θJA
R
θJA
Vfb
Vsd
°C/W
°C/W
°C/W
°C/W
°C/W
°C/W
°C/W
°C/W
Vdc
Vdc
Vdc
°C
°C
Rating
Symbol
Value
Unit
ÁÁÁ
Á
Á
Á
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
Á
Á
Á
ÁÁÁ
Á
Á
Á
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
Á
Á
Á
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
Á
Á
Á
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
Á
Á
Á
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
Á
Á
Á
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
Á
Á
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
Á
Á
Á
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
ÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁÁ
Á
Á
Shutdown Input Voltage
Error Comparator Output Voltage
Operating Junction Temperature
Storage Temperature Range
Verr
TJ
–40 to +125
–65 to +150
Tstg
NOTE:
1. The Junction–to–Ambient Thermal Resistance is determined by PC board copper area per Figure 26.
2. ESD data available upon request.
ELECTRICAL CHARACTERISTICS
(Vin = VO + 1.0 V, IO = 100
µA,
CO = 1.0
µF,
TJ = 25°C [Note 1], unless
Characteristic
Output Voltage, 5.0 V Versions
Vin = 6.0 V, IO = 100
µA,
TJ = 25°C
LP2950C–5.0/LP2951C
LP2950AC–5.0/LP2951AC
TJ = – 40 to +125°C
LP2950C–5.0/LP2951C
LP2950AC–5.0/LP2951AC
Vin = 6.0 to 30 V, IO = 100
µA
to 100 mA, TJ = – 40 to +125°C
LP2950C–5.0/LP2951C
LP2950AC–5.0/LP2951AC
Output Voltage, 3.3 V Versions
Vin = 4.3 V, IO = 100
µA,
TJ = 25°C
LP2950C–3.3/LP2951C–3.3
LP2950AC–3.3/LP2951AC–3.3
TJ = – 40 to +125°C
LP2950C–3.3/LP2951C–3.3
LP2950AC–3.3/LP2951AC–3.3
Vin = 4.3 to 30 V, IO = 100
µA
to 100 mA, TJ = – 40 to +125°C
LP2950C–3.3/LP2951C–3.3
LP2950AC–3.3/LP2951AC–3.3
Output Voltage, 3.0 V Versions
Vin = 4.0 V, IO = 100
µA,
TJ = 25°C
LP2950C–3.0/LP2951C–3.0
LP2950AC–3.0/LP2951AC–3.0
TJ = – 40 to +125°C
LP2950C–3.0/LP2951C–3.0
LP2950AC–3.0/LP2951AC–3.0
Vin = 4.0 to 30 V, IO = 100
µA
to 100 mA, TJ = – 40 to +125°C
LP2950C–3.0/LP2951C–3.0
LP2950AC–3.0/LP2951AC–3.0
Symbol
VO
4.950
4.975
4.900
4.940
4.880
4.925
VO
3.267
3.284
3.234
3.260
3.221
3.254
VO
2.970
2.985
2.940
2.964
2.928
2.958
3.000
3.000
–
–
–
–
3.300
3.300
–
–
–
–
5.000
5.000
–
–
–
–
Min
Typ
otherwise noted.)
Max
Unit
V
5.050
5.025
5.100
5.060
5.120
5.075
V
3.333
3.317
3.366
3.340
3.379
3.346
V
3.030
3.015
3.060
3.036
3.072
3.042
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3
LP2950
ELECTRICAL CHARACTERISTICS (continued)
(Vin = VO + 1.0 V, IO = 100
µA,
CO = 1.0
µF,
TJ = 25°C [Note 1], unless
otherwise noted.)
Characteristic
Line Regulation (Vin = VO(nom) +1.0 V to 30 V) [Note 2]
LP2950C–XX/LP2951C/LP2951C–XX
LP2950AC–XX/LP2951AC/LP2951AC–XX
Load Regulation (IO = 100
µA
to 100 mA)
LP2950C–XX/LP2951C/LP2951C–XX
LP2950AC–XX/LP2951AC/LP2951AC–XX
Dropout Voltage
IO = 100
µA
IO = 100 mA
Supply Bias Current
IO = 100
µA
IO = 100 mA
Dropout Supply Bias Current (Vin = VO(nom) – 0.5 V,
IO = 100
µA)
[Note 2]
Current Limit (VO Shorted to Ground)
Thermal Regulation
Output Noise Voltage (10 Hz to 100 kHz) [Note 3]
CL = 1.0
µF
CL = 100
µF
LP2951A/LP2951AC ONLY
Reference Voltage (TJ = 25°C)
LP2951C/LP2951C–XX
LP2951AC/LP2951AC–XX
Reference Voltage (TJ = – 40 to +125°C)
LP2951C/LP2951C–XX
LP2951AC/LP2951AC–XX
Reference Voltage (TJ = – 40 to +125°C)
IO = 100
µA
to 100 mA, Vin = 23 to 30 V
LP2951C/LP2951C–XX
LP2951AC/LP2951AC–XX
Feedback Pin Bias Current
ERROR COMPARATOR
Output Leakage Current (VOH = 30 V)
Output Low Voltage (Vin = 4.5 V, IOL = 400
µA)
Upper Threshold Voltage (Vin = 6.0 V)
Lower Threshold Voltage (Vin = 6.0 V)
Hysteresis (Vin = 6.0 V)
SHUTDOWN INPUT
Input Logic Voltage
Logic “0” (Regulator “On”)
Logic “1” (Regulator “Off”)
Shutdown Pin Input Current
Vshtdn = 2.4 V
Vshtdn = 30 V
Regulator Output Current in Shutdown Mode
(Vin = 30 V, Vshtdn = 2.0 V, VO = 0, Pin 6 Connected to Pin 7)
Vshtdn
0
2.0
Ishtdn
–
–
Ioff
–
35
450
3.0
50
600
10
µA
–
–
0.7
30
µA
V
Ilkg
VOL
Vthu
Vthl
Vhy
–
–
40
–
–
0.01
150
45
60
15
1.0
250
–
95
–
µA
mV
mV
mV
mV
Vref
1.210
1.220
Vref
1.200
1.200
Vref
1.185
1.190
IFB
–
–
–
15
1.285
1.270
40
nA
–
–
1.270
1.260
V
1.235
1.235
1.260
1.250
V
V
Symbol
Regline
–
–
Regload
–
–
VI – VO
–
–
ICC
–
–
ICCdropout
ILimit
Regthermal
Vn
–
–
–
–
–
93
4.0
110
220
0.05
126
56
120
12
170
300
0.20
–
–
30
350
80
450
µA
mA
µA
mA
%/W
µVrms
0.13
0.05
0.20
0.10
mV
0.08
0.04
0.20
0.10
%
Min
Typ
Max
Unit
%
NOTES:
1. Low duty pulse techniques are used during test to maintain junction temperature as close to ambient as possible.
2. VO(nom) is the part number voltage option.
3. Noise tests on the LP2951 are made with a 0.01
µF
capacitor connected across Pins 7 and 1.
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4
LP2950
DEFINITIONS
Dropout Voltage
– The input/output voltage differential
at which the regulator output no longer maintains regulation
against further reductions in input voltage. Measured when
the output drops 100 mV below its nominal value (which is
measured at 1.0 V differential), dropout voltage is affected
by junction temperature, load current and minimum input
supply requirements.
Line Regulation
– The change in output voltage for a
change in input voltage. The measurement is made under
conditions of low dissipation or by using pulse techniques
such that average chip temperature is not significantly
affected.
Load Regulation
– The change in output voltage for a
change in load current at constant chip temperature.
Maximum Power Dissipation
– The maximum total
device dissipation for which the regulator will operate
within specifications.
Bias Current
– Current which is used to operate the
regulator chip and is not delivered to the load.
Figure 1. Quiescent Current
10
LP2950/LP2951 BIAS CURRENT (mA)
6.0
5.0
Vout , OUTPUT VOLTAGE (V)
1.0
4.0
3.0
2.0
1.0
0
RL = 50
Ω
LP2951C
TA = 25°C
RL = 50 k
Output Noise Voltage
– The rms ac voltage at the output,
with constant load and no input ripple, measured over a
specified frequency range.
Leakage Current
– Current drawn through a bipolar
transistor collector–base junction, under a specified
collector voltage, when the transistor is “off”.
Upper Threshold Voltage
– Voltage applied to the
comparator input terminal, below the reference voltage
which is applied to the other comparator input terminal,
which causes the comparator output to change state from a
logic “0” to “1”.
Lower Threshold Voltage
– Voltage applied to the
comparator input terminal, below the reference voltage
which is applied to the other comparator input terminal,
which causes the comparator output to change state from a
logic “1” to “0”.
Hysteresis
– The difference between Lower Threshold
voltage and Upper Threshold voltage.
Figure 2. Dropout Characteristics
0.1
0.01
0.1
1.0
10
100
0
1.0
2.0
3.0
4.0
5.0
6.0
IL, LOAD CURRENT (mA)
Vin, INPUT VOLTAGE (V)
Figure 3. Input Current
250
200
BIAS CURRENT (
µ
A)
0.1 mA Load Current
150
100
No Load
50
0
0
5.0
10
15
20
25
Vin, INPUT VOLTAGE (V)
5.00
4.99
4.98
4.97
4.96
Figure 4. Output Voltage versus Temperature
Vout , OUTPUT VOLTAGE (V)
LP2951C
4.95
– 50
0
50
100
150
200
TA, AMBIENT TEMPERATURE (°C)
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