1
FN9054.1
ISL72991RH
Radiation Hardened Negative Low
Dropout Adjustable Voltage Regulator
The radiation hardened ISL72991RH is a low dropout
adjustable negative regulator with an output voltage range of
-2.25V to -26V. The device features a 1A output current
capability, an adjustable current limit pin (I
LIM
) and a
shutdown pin (SD) for easy on/off control.
The device incorporates unique circuitry that enables
precision performance over the -55C to +125C temperature
range and post-irradiation. Specifications include a reference
voltage of -1.25V +40mV/-50mV (max), line regulation of
25mV (max), and load regulation of 15mV (max).
Constructed with the Intersil dielectrically isolated Rad Hard
Silicon Gate (RSG) BiCMOS process, these devices are
immune to Single Event Latch-up and have been specifically
designed to provide highly reliable performance in harsh
radiation environments.
Specifications for Rad Hard QML devices are controlled
by the Defense Supply Center in Columbus (DSCC). The
SMD numbers listed here must be used when ordering.
Detailed Electrical Specifications for these devices are
contained in SMD 5962-02503. A `hotlink' is provided on
the Intersil website for downloading.
Pinout
ISL72991RHF (FLATPACK CDFP3-F28)
TOP VIEW
Features
Electrically Screened to DSCC SMD # 5962-02503
QML Qualified per MIL-PRF-38535 Requirements
Radiation Environment
- Total Dose (Max) . . . . . . . . . . . . . . . . . . . . 300krad(SI)
- Latch-Up Immune
Line Regulation . . . . . . . . . . . . . . . . . . . . . . 25mV (max)
Load Regulation . . . . . . . . . . . . 12mV (typ); 15mV (max)
Output Voltage Range . . . . . . . . . . . . . . . . -2.25V to -26V
Dropout Voltage (100mA). . . . . . . . 0.2V (typ); 0.3V (max)
Dropout Voltage (1A) . . . . . . . . . . . . . . . . . . . . . .1V (max)
Minimum Load Current. . . . . . . . . . . . . . . . . . . . . . .3.0mA
TTL Input-Level Shutdown (SD); Low = On
Applications
Switching Power Supplies
DC/DC Converters
Motor Controllers
1
2
3
4
5
6
7
8
9
10
11
12
13
14
28
27
26
25
24
23
22
21
20
19
18
17
16
15
VIN
VIN
NC
NC
NC
NC
NC
NC
NC
NC
GND
ILIM
VOUT
VOUT
VIN
VIN
NC
NC
NC
NC
NC
NC
NC
NC
ADJ
SD
VOUT
VOUT
Ordering Information
ORDERING NUMBER
INTERNAL
MKT. NUMBER
TEMP. RANGE
(C)
5962F0250301VXC
ISL72991RHVF
-55 to 125
5962F0250301QXC
ISL72991RHQF
-55 to 125
5962F0250301V9A
ISL72991RHVX
-55 to 125
ISL72991RHF/Proto
ISL72991RHF/Proto
-55 to 125
Data Sheet
June 2004
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 321-724-7143
|
Intersil (and design) is a registered trademark of Intersil Americas Inc.
Copyright Intersil Americas Inc. 2002, 2004. All Rights Reserved.
All other trademarks mentioned are the property of their respective owners.
2
Application Information
Typical User Application:
Output Voltage Programming
The output voltage of the regulator can be programmed with
two external resistors and is described by the following
equation: V
OUT
= V
REF
x (1+R2/R1) - (I
ADJ
x R2).
Output Current Limit Programming
The output current limit threshold of the regulator can be
programmed with a single external resistor connected from
I
LIM
to ground. The current flowing into the I
LIM
pin is
described by the following equation: I
LIM
= 1V/(R
CL
+ 2400).
The graph below shows the relationship between I
LIM
and
the output current limit threshold, I
OUT_LIM
.
Capacitor Selection
An input capacitor is required if the regulator is located more
than 6 inches from power supply filter capacitors. A 10F
solid tantalum capacitor is recommended.
An output capacitor of at least 10F must be used to insure
stability of the regulator. Additional capacitance may be
added as required to improve the dynamic response of the
regulator. Solid tantalum and/or ceramic capacitors are
recommended.
Loop Compensation
The output capacitor and ESR comprise a zero in the loop
transfer function that must be compensated with a pole to
insure loop stability in accordance with the following
equation: C
C
x R2 = C
OUT
x ESR. The compensating
capacitor should be a low ESR ceramic type.
Layout Guidelines
The stability of the regulator is sensitive to layout. It is
strongly recommended that a continuous copper ground
plane (1 ounce or greater) be used. In addition, component
lead lengths and interconnects should be minimized, but
should not exceed 1/2 inch. Finally, the return lead of the
compensation capacitor (C
C
) should be connected as close
as possible to the GND pin of the IC.
ISL72991RH
VIN
ILIM
SD
GND
VOUT
ADJ
VIN
CIN
RCL
R1
CC
R2
COUT
VOUT
FIGURE 1. TYPICAL APPLICATION SCHEMATIC
FIGURE 2. I
OUT_LIM
vs I
LIM
I
LIM
(A)
I
O
U
T_LIM
(A
)
ISL72991RH
3
All Intersil U.S. products are manufactured, assembled and tested utilizing ISO9000 quality systems.
Intersil Corporation's quality certifications can be viewed at www.intersil.com/design/quality
Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without
notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be accurate and
reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result
from its use. No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries.
For information regarding Intersil Corporation and its products, see www.intersil.com
Die Characteristics
DIE DIMENSIONS:
5870
m x 5210m (231.1mils x 205.1mils)
Thickness: 483
m 25.4m (19mils 1mil)
INTERFACE MATERIALS:
Glassivation:
Type: PSG (Phosphorous Silicon Glass)
Thickness: 8.0k
1.0k
Top Metallization:
Type: AlSiCu
Thickness: 16.0k
2k
Substrate:
Radiation Hardened Silicon Gate,
Dielectric Isolation
Backside Finish:
Silicon
ASSEMBLY RELATED INFORMATION:
Substrate Potential:
Unbiased (DI)
ADDITIONAL INFORMATION:
Worst Case Current Density:
<2.0 x 10
5
A/cm
2
Transistor Count:
Metallization Mask Layout
ISL72991RH
ISL72991RH
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