Standard Products
VRG8663
Low Drop Out(LDO)Adjustable Regulator
Negative Voltage
Radiation Tolerant
www.aeroflex.com/voltreg
January 7, 2009
FEATURES
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Manufactured using
Linear Technology Corporation
®
Space Qualified RH1185 die
Radiation performance
- Total dose: 100 krads(Si), Dose rate = 50 - 300 rads(Si)/s
Thermal shutdown
Output voltage adjustable: -2.37 to -25V
Dropout voltage: -1.3V at 3.0Amps
5-Terminal
Output current: 3A
Voltage reference: -2.370V ±3%
Load regulation: 0.9% max
Line regulation: 0.04% max
Ripple rejection: >60dB
Packaging
- Hermetic Surface Mount Power Package
- 5 Pads, .301"W x .550"L x .130"Ht max
- Weight - 1.2 gm max
Designed for aerospace and high reliability space applications
DSCC SMD 5962-09207 pending
Note: Aeroflex Plainview does not currently have a DSCC certified Radiation Hardened Assurance Program.
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DESCRIPTION
The Aeroflex Plainview VRG8663 consists of a Negative Adjustable (RH1185) LDO voltage regulator capable of
supplying 3.0Amps over the output voltage range as defined under recommended operating conditions. The VRG8663
offers excellent line and load regulation specifications and ripple rejection. Dropout (V
IN
- V
OUT
) decreases at lower
load currents.
The VRG8663 serves a wide variety of applications including High Efficiency Linear Regulators, Post Regulators for
Switching Supplies, Constant Current Regulators, Battery Chargers and Microprocessor Supply.
The VRG8663 has been specifically designed to meet exposure to radiation environments and is configured for a SMD
power package. It is guaranteed operational from -55°C to +125°C. Available screened to MIL-STD-883, the
VRG8663 is ideal for demanding military and space applications.
For detailed performance characteristic curves, applications information and typical applications see the
latest
Linear Technology Corporation
®
data sheets for their RH/LT1185, which is available on-line at
www.linear.com.
3
V
OUT
RH1185
V
IN
5
2
1
Reference
Feedback
GND
4
FIGURE 1 – BLOCK DIAGRAM / SCHEMATIC
SCD8663 Rev B
ABSOLUTE MAXIMUM RATINGS
PARAMETER
Input Voltage
Lead temperature (soldering 10 Sec)
Input Output Differential
Feedback & Reference Voltage
Output Voltage
ESD
Operating Junction Temperature Range
Storage Temperature Range
RANGE
-35
300
-30
-7
-30
2000
1/
-55 to +150
-65 to +150
UNITS
V
DC
°C
V
DC
V
DC
V
DC
V
°C
°C
NOTICE: Stresses above those listed under "Absolute Maximums Rating" may cause permanent damage to the device. These are stress rating only;
functional operation beyond the "Operation Conditions" is not recommended and extended exposure beyond the "Operation Conditions"
may effect device reliability.
RECOMMENDED OPERATING CONDITIONS
PARAMETER
Output Voltage Range
Input Output Differential
Case Operating Temperature Range
RANGE
-2.37 to -25
-1 to -28
-55 to +125
UNITS
V
DC
V
DC
°C
ELECTRICAL PERFORMANCE CHARACTERISTICS 2/
PARAMETER
Reference Voltage
(At pin 6) 9/
Dropout Voltage
6/
SYM
V
REF
CONDITIONS (P
≤
P
MAX
)
1mA < I
OUT
< 3A, V
IN
- V
OUT
= -1.2V to -28V, V
OUT
= -5V.
Not tested at +125°C.
I
OUT
= 0.5A, V
OUT
= -5V
V
DROP
I
OUT
= 3A, V
OUT
= -5V
MIN
-2.30
-
-
-
-
-
3.1
2.0
1.0
0.2
2.5
0.8
-
-
-
MAX
-2.44
-0.47
-1.30
0.04
0.90
-5.0
4.6
4.4
2.8
1.3
3.65
1.5
3.5
59
36
UNITS
V
V
V
%/V
%
V
A
A
A
A
A
A
mA
mA/A
mA/A
Line Regulation
Load Regulation
10/
10/
7/
Δ
V
OUT
-1.0V < V
IN
- V
OUT
< -20V, V
OUT
= -5V
Δ
V
IN
Δ
V
OUT
5mA < I
OUT
< 3A, V
IN
- V
OUT
= -1.5V to -10V, V
OUT
= -5V
Δ
I
OUT
V
IN MIN
I
OUT
= 3A , V
OUT
= V
REF
-1.5V < V
IN
- V
OUT
< -10V
Minimum Input Voltage
Internal Current Limit (See
Graph for Guaranteed Curve
LT1185).
Not tested at +125°C.
I
CL
V
IN
- V
OUT
= -15V
V
IN
- V
OUT
= -20V
V
IN
- V
OUT
= -28V
R
LIM
= 5K
Ω
12/
R
LIM
= 15K
Ω
12/
I
OUT
= 5mA, V
OUT
= V
REF
, -4V < V
IN
< -25V
V
IN
– V
OUT
= V
SAT
V
IN
– V
OUT
≥
-2V
11/
External Current Limit
Quiescent Supply Current 8/
Supply Current Change with
Load
I
LIM
I
Q
I
Q
Δ
SCD8663 Rev B 1/7/09
2
Aeroflex Plainview
ELECTRICAL PERFORMANCE CHARACTERISTICS 2/ (con’t)
PARAMETER
Thermal Regulation
(See application info LT1185)
5/
Thermal Resistance
(Junction to Case) 3/
SYM
-
CONDITIONS (P
≤
P
MAX
)
V
IN
–V
OUT
= -10V, I
OUT
= 5mA to 2A, T
C
= +25°C
MIN
-
MAX
0.014
UNITS
%/W
Θ
JC
-
3
°C/W
Notes
1 Meets ESD testing per MIL-STD-883, method 3015, Class 2.
2. Unless otherwise specified, these specifications apply for post radiation and -55°C < Tc < +125°C.
5. Not tested. Shall be guaranteed by design, characterization, or correlation to other tested parameters.
6. Dropout voltage is tested by reducing input voltage until the output drops 1% below its nominal value. Tests are done at 0.5A and 3A. The
power transistor looks basically like a pure resistance in this range so that minimum differential at any intermediate current can be calculated
by interpolation; V
DROPOUT
= 0.25V + (0.25
Ω
x I
OUT
). For load current less than 0.5A, see Figure 3.
7. “Minimum input voltage” is limited by base emitter voltage drive of the power transistor section, not saturation as measured in Note 3. For
output voltages below 4V, “minimum input voltage” specification may limit dropout voltage before transistor saturation limitation.
8. Supply current is measured on the ground pin, and does not include load current, RLIM, or output divider current.
9. The 25W power level is guaranteed for an input-output voltage of 8.3V to 17V. At lower voltages the 3Amp limit applies, and at higher
voltages the internal power limiting may restrict regulator power below 25W.
10. Line and load regulation are measured on a pulse basis with a pulse width of 2ms, to minimize heating. DC regulation will be affected by
thermal regulation and temperature coefficient of the reference.
11. V
SAT
is the maximum specified dropout voltage: 0.25V + (0.25 x I
OUT
).
12. Current limit is programmed with a resistor from REF pin to GND pin. R
LIM
= 15KΩ/I
LIM
.
SCD8663 Rev B 1/7/09
3
Aeroflex Plainview
60
50
40
Maximum Power
Dissipation
(Watts)
30
20
10
0
0
20
40
60
80
100
120
140
Case Temperature (°C)
FIGURE 2 – MAXIMUM POWER vs CASE TEMPERATURE
The maximum Power dissipation is limited by the thermal shutdown function of the regulator chip in the VRG8663. The graph
above represents the achievable power before the chip shuts down. The line in the graph represents the maximum power
dissipation of the VRG8663 This graph is based on the maximum junction temperature of 150°C and a thermal resistance (
Θ
JC
)
of 3°C/W.
FIGURE 3 – RH1185 DROPOUT VOLTAGE CURVE
FIGURE 4 – RH1185 INTERNAL CURRENT LIMIT
SCD8663 Rev B 1/7/09
4
Aeroflex Plainview
The RH1185 output voltage is set by two external resistors.
Internal reference voltage is trimmed to
2.37V so that a standard 1% 2.37k resistor (R1) can be
used to set divider current at 1mA. R2 is then selected
from:
+
+
PARASITIC
LEAD RESISTANCES
C
1
R
LIM
2
REF
4
GND
FB
1
r
a
– r
b
+
I
GND
C
2
R1
*
2.37k
LOAD
+
V
IN
+
R2 =
(V
OUT
– 2.37) R1
V
REF
V
OUT
for R1 = 2.37k and V
REF
= 2.37V, this reduces to:
R2 =
V
OUT
– 2.37
10
-3
–
5
V
IN
VRG8663
VRG8663
(RH1185)
(RH1185)
V
OUT
3
R2
–
suggested values of 1% resistors are shown.
V
OUT
2.5V
3.3V
.
5V
12V
15V
R2 WHEN R1 = 2.37k
130Ω
930Ω
2.67k
9.76k
12.7k
*R1 SHOULD BE CONNECTED DIRECTLY TO GROUND LEAD, NOT TO THE LOAD,
SO THAT r
a
≈
0Ω. THIS LIMITS THE OUTPUT VOLTAGE ERROR TO (I
GND
)(r
b
).
ERRORS CREATED BY r
a
ARE MULTIPLIED BY (1 + R2/R1). NOTE THAT V
OUT
INCREASES
WITH INCREASING GROUND PIN CURRENT. R2 SHOULD BE CONNECTED
DIRECTLY TO LOAD FOR REMOTE SENSING. C1 = C2 > 2µF Tantalum.
SETTING OUTPUT VOLTAGE
R1 & R2 LOCATION & PROPER CONNECTION OF
POSITIVE SENSE LEAD
FIGURE 5 – BASIC VRG8663 ADJUSTABLE REGULATOR APPLICATION
SCD8663 Rev B 1/7/09
5
Aeroflex Plainview
