Ultra Low Dropout
IRUH50PA23A1M
Positive Adjustable Linear Regulator +5.0Vin at 3.0A
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1
Features:
n
Total dose to 1.0Mrad(Si) and low dose
capability to 500 Krad(Si) allows use in
space applications
n
Single Event latchup Immune
LET = 84 MeV/(mg/cm
2
)
Fluency = 1 x 10
9
Ions/cm
2
n
Low noise, higher efficiency
n
Ultra low dropout voltage of 0.4V@ 3A out
significantly reduces power consumption
n
Remote shutdown permits power
sequencing to be easily implemented
n
Hermetic 8-lead flat pack ensures higher
reliability
n
Space Level Screened
n
This part is also available in MO-078 Package
as IRUH50PA23B1M
The IRUH50PA23A1M is a space qualified, ultra low
dropout linear regulator designed specifically for space
applications. This product has been characterized to a total
ionizing dose of 1.0Mrad(Si) per MIL-STD-883, Method
1019 at both high and low dose rates under biased and
unbiased conditions to account for ELDRS effects in bipolar
devices. The ultra low dropout voltage of 0.4V @ 3A makes
the part particularly useful for applications requiring low
noise and higher efficiency.
01/09/06
Absolute Maximum Ratings
Parameter
Symbol
Value
Units
Output Current
I
O
3.5
A
Input Voltage
V
IN
7.0
Output Voltage
V
OUT
1.265V To (V
IN
- 0.4V)
Power Dissipation, T
C
= 25C
P
TOT
19
W
Thermal Resistance, Junction to Case
R
THJC
6.5
C/W
Operating Temperature Range
T
J
-55 to +125
Storage Temperature Range
T
S
-65 to +150
C
Lead Temperature
T
L
300
V
Product Summary
Part Number
Dropout
I
O
V
in
V
out
IRUH50PA23A1M
0.4V
3.0A
5.0V
1.265V To (V
IN
- 0.4V)
8-LEAD FLAT PACK
PD-97032A
2
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IRUH50PA23A1M
Pre-Radiation
Pre-Radiation
For notes, please refer to page 3
Electrical Characteristics @T
C
= 25C (Unless Otherwise Specified)
Parameter
Test Conditions
Symbol
Min.
Typ. Max. Units
Input Voltage Range - Operating I
O
= 3.0A
V
IN
4.5
-
6.5
Reference Voltage
V
REF
1.252
1.265
1.278
Line Regulation
4.5V
V
IN
5.5V, I
O
= 50mA
V
LINE
-0.25
-
+0.25
% / V
Load Regulation
V
IN
= 5.0V, 50mA
I
OUT
3.0A
V
LOAD
-1.0
-
1.0
% / A
Dropout Voltage
I
O
= 3.0A, V
OUT
= 2.5V
V
DROP
-
-
0.4
V
Current Limit
V
IN
= 5.0V, Overcurrent Latchup
I
LATCH
3.0
-
-
A
Ripple Rejection
F = 120Hz, I
O
= 50mA
65
-
-
dB
Shutdown Source Current
V
SHDN
= 5.0V
I
SHDN
-
200
-
A
Shutdown Pin Threshold
V
IN
= 5.0V
V
SHDN
1.0
-
1.6
Output Voltage at Shutdown
V
IN
= 5.0V, I
O
= 50mA, V
SHDN
= +5.0V V
OUT (SHDN)
-0.1
-
+0.1
V
V
Electrical Characteristics @T
C
= -55C to +125C
Parameter
Test Conditions
Symbol
Min.
Typ.
Max. Units
Input Voltage Range - Operating I
O
= 3.0A
V
IN
4.5
-
6.5
Reference Voltage
V
REF
1.225
1.265
1.305
Line Regulation
4.5V
V
IN
5.5V, I
O
= 50mA
V
LINE
-0.5
-
+0.5
% / V
Load Regulation
V
IN
= 5.0V, 50mA
I
OUT
3.0A
V
LOAD
-2.0
-
2.0
% / A
Dropout Voltage
I
O
= 3.0A, V
OUT
= 2.5V
V
DROP
-
-
0.4
V
Current Limit
V
IN
= 5.0V, Overcurrent Latchup
I
LATCH
3.0
-
-
A
Ripple Rejection
F = 120Hz, I
O
= 50mA
65
-
-
dB
Shutdown Source Current
V
SHDN
= 5.0V
I
SHDN
-
200
-
A
Shutdown Pin Threshold
V
IN
= 5.0V
V
SHDN
1.0
-
1.6
Output Voltage at Shutdown
V
IN
= 5.0V, I
O
= 50mA, V
SHDN
= +5.0V V
OUT (SHDN)
-0.1
-
+0.1
V
V
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3
IRUH50PA23A1M
Notes for Electrical Characteristic Tables
V
Shutdown
ramp from 0.8V to 4.8V, output monitored for a 100mV drop below the nominal specification for V
out
Post-Radiation
Electrical Characteristics @T
C
= 25C (Unless Otherwise Specified)
Parameter
Test Conditions
Symbol
Min.
Typ. Max. Units
Line Regulation
4.5V
V
IN
5.5V, I
O
= 50mA
V
LINE
-0.5
-
+0.5
% / V
Load Regulation
V
IN
= 5.0V, 50mA
I
OUT
3.0A
V
LOAD
-2.0
-
2.0
% / A
Current Limit
V
IN
= 5.0V
I
MAX
3.0
-
-
A
Ripple Rejection
F = 120Hz, I
O
= 50mA
40
-
-
dB
Output Voltage at Shutdown
V
IN
= 5.0V, I
O
= 50mA, V
SHDN
= +5.0V V
OUT (SHDN)
-0.1
-
+0.1
V
4
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IRUH50PA23A1M
Pre-Radiation Characteristics
Fig 1. Ripple Rejection Vs Frequency
OMR9601 Ripple Rejection vs. Frequency
0
20
40
60
80
100
120
100
1,000
10,000
100,000
1,000,000
Frequency (Hz)
(
db)
3A
1.5A
.75A
.50A
Radiation Performance Characteristics
Test
Conditions
Min
Typ
Unit
MIL-STD-883, Method 1019
Operating Bias applied during exposure
Full Rated Load, Vin=5.0V
Single Event effects
Heavy Ions (LET)
SEU, SEL, SEGR, SEB
Operating Bias applied during exposure
Full Rated Load, Vin=5.0V
Neutron Fluence
MIL-STD-883, Method 1017
Total Ionizing Dose (Gamma)
Krads (Si)
1.00E+09
1.00E+13
84
MeV*cm
2
/mg
1,000
Neutrons/cm
2
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5
IRUH50PA23A1M
Fig 2. Typical Application Circuit
V
out =
V
ref
X
( 1+ R1/1000 )
Recommended input capacitance for a generic application is a 100
F, 16V tantalum capacitor. However, the
input capacitance is not critical to the stability of the regulator and is therefore application dependant. In
designs with a clean bus voltage that is situated close to the input of the regulator, only a small ceramic
capacitor will be needed to decouple high frequency noise. On the other hand , in designs with a noisy bus,
a larger capacitor will be needed. Care should be taken to ensure that the input to the regulator is sufficiently
free of noise and disturbances.
Output Capacitance
Like most ultra low dropout voltage regulators, IRUH50PA23A1M requires the use of output capacitors as
part of the device frequency compensation. The device requires a minimum of 220
F tantalum to ensure
stability.
Many different types of capacitor are available and have widely varying characteristics. These capacitors
differ in capacitor tolerance, equivalent series resistance (ESR), equivalent series inductance and capacitance
temperature coefficient. The IRUH50PA23A1M frequency compensation optimizes frequency response with
low ESR capacitors. In general, use capacitors with an ESR of less than 50m
for heavy load applications.
High quality bypass capacitors must be also be used to limit the high frequency noise generated by the load.
Multiple small ceramic capacitors are typically required to limit parasitic inductance (ESL) and ESR in the
capacitors to acceptable levels.
The upper limit of the capacitance is governed by the delayed over-current latch function of the regulator. The
regulator has a protection circuit that will latch the device off in the event of a short circuit. However, since it is
known that the regulator will draw a large in-rush current upon startup, the latch-off is delayed by about 10ms
to allow the outout capacitors to charge to a steady state without shutting down. During this period, the
regulator will have an output current at its maximum of around 5A typical. Therefore, the maximum output
capacitance can be as high as 20,000
F without causing device to latch-off during start-up.
Input Capacitance
IRUH50PA23A1M
Vout
Vin
SHDN
GND
100uF 16V
Tantalum
1.0uFX10
CeramicX7R
1000uF 6.3V
Low ESR Tantalum
Vin
Vout
Ground
R1
ADJUST
RESISTOR
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