Standard Products
Datasheet
VRG8687/VRG8688
Dual Voltage Regulator, 3.0 Amp, Positive
Low Dropout (LDO), Adjustable
Radiation Tolerant
www.aeroflex.com/voltreg
April 9, 2014
FEATURES
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Manufactured using
Space Qualified RH1084 die
Radiation performance
- Total dose > 100 krad (Si),
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Packaging – Hermetic metal
Dose rate = 50 - 300 rads(Si)/s
- Thru-hole or Surface mount
- 8 Leads, .755"L x .415"W x .200"Ht
Two-Independent voltage regulators
- Power package
Thermal shutdown
- Weight - 6 gm max
Output voltage adjustable: 1.25V to 23V
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Designed for aerospace and high reliability space
Dropout voltage: 1.80V at 3.0Amps
applications
3-Terminal
Output current: 3.0Amps
Voltage reference: 1.25V +2%, -3.2%
Load regulation: 0.35% max
Line regulation: 0.25% max
Ripple rejection: >60dB
Aeroflex Plainview’s Radiation Hardness Assurance Plan is DLA Certified to MIL-PRF-38534, Appendix G.
DESCRIPTION
The Aeroflex Plainview VRG8687/8688 consists of two Positive Adjustable (RH1084) LDO voltage regulators each
capable of supplying 3.0Amps over the output voltage range as defined under recommended operating conditions. The
VRG8687/8688 offers excellent line and load regulation specifications and ripple rejection. There is full electrical
isolation between the regulators and each regulator to the package.
The VRG8687/8688 serves a wide variety of applications including SCSI-2 Active Terminator, High Efficiency
Linear Regulators, Post Regulators for Switching Supplies, Constant Current Regulators, Battery Chargers and
Microprocessor Supply.
The VRG8687/8688 has been specifically designed to meet exposure to radiation environments. The VRG8687 is
configured for a Thru-Hole 8 lead metal power package and the VRG8688 is configured for a Surface Mount 8 lead
metal power package. It is guaranteed operational from -55°C to +125°C. Available screened in accordance with
MIL-PRF-38534, the VRG8687/8688 is ideal for demanding military and space applications.
Dropout (V
IN
- V
OUT
) decreases at lower load currents for both regulators.
1
A
DJ
_1
2
V
OUT
_1
RH1084
Positive
Regulator
S
ENSE
_1
V
IN
_1
8
A
DJ
_2
V
OUT
_2
RH1084
Positive
Regulator
S
ENSE
_2
V
IN
_2
5
6
3
7
4
FIGURE 1 – BLOCK DIAGRAM / SCHEMATIC
SCD8687 Rev C
ABSOLUTE MAXIMUM RATINGS
Parameter
Input Voltage
Input Output Differential
Load Current, maximum
Output Voltage
ESD (MIL-STD-883, M3015, Class 2)
Operating Junction Temperature Range
Storage Temperature Range
Thermal Resistance, Junction to case
JC
Lead temperature (soldering 10 Sec)
Rating
+25
25
6.0
+25
2000 to 3999
-55 to +150
-65 to +150
5
300
Units
V
DC
V
DC
A
V
DC
V
°C
°C
°C/W
°C
NOTICE: Stresses above those listed under "Absolute Maximum Ratings" 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 3/
Case Operating Temperature Range
Range
1.25 to 23.00
1.8 to 24.0
-55 to +125
Units
V
DC
V
DC
°C
ELECTRICAL PERFORMANCE CHARACTERISTICS 1/
U
NLESS OTHERWISE SPECIFIED
: -55°C
T
C
+125°C
Conditions (P
P
MAX
)
1.5V < (V
IN
- V
OUT
) < 15V, 10mA < I
OUT
< 3.0A
Parameter
Reference Voltage 3/, 2/
Line Regulation 3/, 2/
Load Regulation 3/, 2/
Dropout Voltage 4/, 2/
Dropout Voltage
Adjust Pin Current 2/
Adjust Pin Current Change 2/
Minimum Load Current 5/, 2/
Current Limit 2/
Ripple Rejection 3/
Thermal Regulation
Symbol
V
REF
Min
Max
Units
V
%
%
V
V
µA
µA
mA
A
dB
%/W
1.210 1.275
-
-
-
-
-
-
-
5.25
60
-
0.25
0.35
1.8
1.4
120
5
10
-
-
0.04
V
OUT
I
LOAD
= 10mA, 1.5V < (V
IN
- V
OUT
) < 15V
V
IN
V
OUT
10mA < I
OUT
< 3.0A, (V
IN
- V
OUT
) = 3V
I
OUT
V
DROP1
V
REF
= 1%, I
OUT
= 5.0A
V
DROP2
V
REF
= 1%, I
OUT
= 3.0A
-
-
I
MIN
I
CL
-
-
10 mA < I
OUT
< 3.0A, 1.5V < (V
IN
- V
OUT
) < 15V
(V
IN
- V
OUT
) = 25V
(V
IN
- V
OUT
) = 5V
I
OUT
= 0.5A, (V
IN
- V
OUT
) = 3V, f = 120Hz,
C
ADJ
= C
OUT
= 25µF
30ms pulse, T
C
= +25°C
Notes:
1/ The manufacturer’s output current rating for the RH1084MK positive regulator integrated circuit is 5.0 Amps. For Compliance with the
Current Density specifictation of MIL-STD-883 Rev. C, the electrical performance characteristics are specified at an output current of
3.0 Amps.
2/ Specification derated to reflect total dose exposure to 100krads (Si) at +25°C.
3/ Line and load regulation are guaranteed up to the maximum power dissipation of 15W per device. Power dissipation is determined by
the input/output differential voltage and the output current. Guaranteed maximum power dissipation will not be available over the full
input/output voltage range.
4/ Dropout voltage is specified over the full output current range of the device.
5/ Not tested. Shall be guaranteed by design, characterization, or correlation to other tested parameters.
SCD8687 Rev C 4/9/14
2
Aeroflex Plainview
60
50
40
Maximum Power
Dissipation
(Watts)
30
20
Both Regulators
1 Regulator
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 each regulator chip in the
VG8687/8688. The graph above represents the achievable power before the chip shuts down. The first line in the
graph represents the maximum power dissipation of the VG8687/8688 with one regulator on (the other off) and the
other line represents both regulators on dissipating equal power. If both regulators are on and one regulator is
dissipating more power that the other, the maximum power dissipation of the VG8687/8688 will fall between the two
lines. This graph is based on the maximum junction temperature of 150°C and a thermal resistance (
JC
) of 5°C/W.
See Note 1/ on page 2
FIGURE 3 – RH1084 SHORT CIRCUIT CURRENT
SCD8687 Rev C 4/9/14
Aeroflex Plainview
3
FIGURE 4 – RH1084 DROPOUT VOLTAGE TYPICAL CURVE
S
ENSE
V
IN
10µF
Tant
.
VRG8687/88
V
REF
ADJ
R1
V
OUT
22µF
Tant
.
V
REF
= 1.25V, I
ADJ
= 55µA
+Reg = V
OUT
= V
REF
(1+R2/R1) + (I
ADJ
x R2)
R2
FIGURE 5 – BASIC RH1084 ADJUSTABLE REGULATOR APPLICATION
SCD8687 Rev C 4/9/14
Aeroflex Plainview
4
TABLE I – PIN NUMBERS vs FUNCTION
PIN
1
2
3
4
5
6
7
8
FUNCTION
ADJ_1
VOUT_1
SENSE_1
VIN_2
ADJ_2
VOUT_2
SENSE_2
VIN_1
.300
.090
8X
.100
.108
ø
.010
CBA
ø
.145 THRU
2x .028
MAX.
M
.150 REF.
8
7
6
5
2° MAX. TYP.
.415
.2075
–C–
R.065 TYP.
4 PLCS
±.003
.220 MAX.
±.005
–A–
.040
.030
DIA.
±.002
1
2
3
4
.720 ±.020
MEASURED
LEAD TIP
ESD/PIN 1
IDENT
.230 MIN
.515
.632
.755
–B–
.122
ø
.010
BCA
ø
.010
M
CBA
Notes:
1. Dimension Tolerance: ±.005 inches
2. Package contains BeO substrate
3. Case electrically isolated
FIGURE 5 – VRG8687 PACKAGE OUTLINE — THRU-HOLE POWER PACKAGE
SCD8687 Rev C 4/9/14
Aeroflex Plainview
5
电源技术
