INTERSIL ISL21440IUZ

Micropower Voltage Reference with Comparator
ISL21440
Features
The ISL21440 is a micropower, FGA™ reference and comparator
on a single chip. Drawing less than 1.8µA supply current over the
full operating temperature range, the ISL21440 operates from a
single 2V to 11V supply and can also be used with split bipolar
supplies.
• 1.8µA Supply Current Over Full Temperature Range
The ISL21440’s on-board reference provides a 1.182V ±0.5%
output. It features programmable hysteresis and TTL/CMOS
compatible outputs that sink and source current. Low Bias
currents permit high value divider resistors for typical circuit
current drains of <2.5µA.
• Temperature Range . . . . . . . . . . . . . . . . . . . .-40°C to +125°C
The low supply current makes the ISL21440 ideal for battery
powered devices in battery level or low voltage monitors circuits.
• Low Battery Detector
The ISL21440 is a pin-compatible, performance upgrade of both
the LTC1440, LTC1540, MAX921 and MAX931.
• Wide Supply Range . . . . . . . . . . . . . . . . . . . . . . . . . . 2V to 11V
• Precision 1.182V ±0.5% Voltage Reference
• Comparator with User Programmable Hysteresis
• 8 Ld MSOP and 8 Ld TDFN Packages
• Pin Compatible Upgrade to MAX921 and LTC1440
Applications
• Low Voltage Reset
• Overvoltage Monitor
• Window Comparator
Vdd
VBAT
1.190
IN+
IN-
1.8M
20k
HYST
REF
V+ = 3V
1.188
V+
+
-
OUT
1.186
LoBAT-
1.184
ISL21440
VREF (V)
2.4M
V+ = 5V
1.182
1.180
1.178
V+ = 2V
1.176
2.4M
V-
GND
1.174
1.172
-40
LOW BATTERY DETECTOR
FIGURE 1. TYPICAL APPLICATION
February 23, 2011
FN6532.2
1
-20
0
20
40
60
80
100
120
TEMPERATURE (°C)
FIGURE 2. REFERENCE VOLTAGE vs TEMPERATURE
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 1-888-468-3774 | Copyright Intersil Americas Inc. 2009-2011. All Rights Reserved
Intersil (and design) is a trademark owned by Intersil Corporation or one of its subsidiaries.
All other trademarks mentioned are the property of their respective owners.
ISL21440
Block Diagram
V+
IN+
+
IN-
OUT
-
HYST
ISL21440
REF
V-
Pin Descriptions
Pin Configuration
ISL21440
(8 LD MSOP, 8 LD TDFN)
TOP VIEW
PIN SYMBOL
GND
1
8
OUT
V-
2
7
V+
IN+
3
6
REF
IN-
4
5
HYST
2
GND
DESCRIPTION
1
GND
Ground pin. Sets the Comparator output low level.
2
V-
Negative Supply Input for Voltage Reference and
Comparator.
3
IN+
Comparator non-inverting input pin. Range: V- to
V+ -1.5V.
4
IN-
Comparator inverting input pin. Range: V- to V+ -1.5V
5
HYST
Comparator Hysteresis input. Accepts a voltage divided
from the Reference output. Range is VREF - 50mV to
VREF. Connect directly to VREF for zero hysteresis.
6
REF
Reference output. Source 2mA and Sink 10µA.
7
V+
Positive Supply Input for Comparator and Reference.
Range is 2.0V to 11.0V
8
OUT
Comparator output, CMOS push-pull. Output swing
referenced to V+ and GND.
FN6532.2
February 23, 2011
ISL21440
Ordering Information
PART NUMBER
(Notes 1, 2, 3)
PART MARKING
VDD RANGE
(V)
TEMP RANGE
(°C)
PACKAGE
(Pb-free)
PKG.
DWG. #
ISL21440IUZ
1440Z
2 to 11
-40 to +125
8 Ld MSOP
M8.118
ISL21440IRTZ
1440
2 to 11
-40 to +125
8 Ld TDFN
L8.3x3G
NOTES:
1. Add “-T*” suffix for tape and reel. Please refer to TB347 for details on reel specifications.
2. These Intersil Pb-free plastic packaged products employ special Pb-free material sets, molding compounds/die attach materials, and 100% matte
tin plate plus anneal (e3 termination finish, which is RoHS compliant and compatible with both SnPb and Pb-free soldering operations). Intersil Pbfree products are MSL classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020.
3. For Moisture Sensitivity Level (MSL), please see device information page for ISL21440. For more information on MSL please see techbrief TB363.
3
FN6532.2
February 23, 2011
ISL21440
Table of Contents
Absolute Maximum Ratings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Thermal Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Environmental Operating Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Recommended Operating Conditions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Analog Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Analog Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Typical Performance Curves. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Device Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Comparator Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Voltage Reference Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Applications Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Handling and Board Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Hysteresis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Board Assembly Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Special Applications Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Typical Applications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Low Battery Detector. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Window Comparator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Package Outline Drawing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Package Outline Drawing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
4
FN6532.2
February 23, 2011
ISL21440
Absolute Maximum Ratings
Thermal Information
Supply Voltage Range, V+ to GND . . . . . . . . . . . . . . . . . . . . . . -0.5V to +12V
IN+, IN- with Respect to V- . . . . . . . . . . . . . . . . . . . . . . . -0.3V to (V+) +0.3V
GND with Respect to V- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.0V to -0.3V
V+ with Respect to V- . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12V to -0.3V
REF, HYST with Respect to V- . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 1.5V
Out with Respect to GND . . . . . . . . . . . . . . . . . . . . . . . . . (V+) +0.3V to -0.3V
Voltage on All Other Pins . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to VCC + 0.3V
ESD Rating
Human Body Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4000V
Machine Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 350V
Charged Device Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2000V
Latch Up (Tested Per JESD-78B; Class 1, Level A) . . . . . . . . . . . . . . 100mA
Thermal Resistance (Typical)
θJA (°C/W) θJC (°C/W)
8 Ld MSOP Package (Notes 5, 7) . . . . . . . . . .
154
55
8 Ld TDFN Package (Notes 5, 6). . . . . . . . . . .
68
8
Maximum Junction Temperature (Plastic Package) . . . . . . . . . . . .+150°C
Storage Temperature Range. . . . . . . . . . . . . . . . . . . . . . . .-65°C to +150°C
Pb-Free Reflow Profile (Note 8). . . . . . . . . . . . . . . . . . . . . . . . see link below
http://www.intersil.com/pbfree/Pb-FreeReflow.asp
Recommended Operating Conditions
Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-40°C to +125°C
Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.7V to 5.5V
Environmental Operating Conditions
X-Ray Exposure (Note 4) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10mRem
CAUTION: Do not operate at or near the maximum ratings listed for extended periods of time. Exposure to such conditions may adversely impact product
reliability and result in failures not covered by warranty.
NOTES:
4. Measured with no filtering, distance of 10” from source, intensity set to 55kV and 70mA current, 30s duration. Other exposure levels should be
analyzed for Output Voltage drift effects. See “Applications Information” on page 11.
5. θJA is measured with the component mounted on a high effective thermal conductivity test board in free air. See Tech Brief TB379 for details.
6. For θJC, the “case temp” location is the center of the exposed metal pad on the package underside.
7. For θJC, the “case temp” location is taken at the package top center.
8. Post-reflow drift for the ISL21440 device voltage reference output will range from 100mV to 1.0mV based on experimental results with devices on
FR4 double sided boards. The design engineer must take this into account when considering the reference voltage after assembly.
Analog Specifications
temperature range, -40°C to +125°C.
SYMBOL
V+= +5.0V. V- = GND = 0V unless otherwise specified, TA = +25°C. Boldface limits apply over the operating
PARAMETER
TEST CONDITIONS
MIN
(Note 10)
TYP
(Note 9)
MAX
(Note 10)
UNITS
11.0
V
0.75
µA
0.85
µA
±3
mV
±3.25
mV
±3.6
mV
±3.75
mV
POWER SUPPLY
V+
Supply Voltage Range
V- = GND
ICC
Supply Current
IN+ = IN- +80mV,
HYST = REF
2.0
0.46
COMPARATOR
VOS
Input Offset Voltage
VCM = 2.5V
MSOP Package
TDFN Package
IIN
VCM
CMRR
Input Leakage Current (IN+, IN-, HYST)
VIN+ = VIN- = 2.5V
MSOP Package
0.1
1.4
nA
TDFN Package
0.1
1.5
nA
3
nA
(V+) - 1.5
V
3
mV/V
3.5
mV/V
4.5
mV/V
5
mV/V
Common-Mode Input Range
Common-Mode Rejection Ratio
VV- to (V+ - 1.5V)
MSOP Package
TDFN Package
5
1.2
1.2
FN6532.2
February 23, 2011
ISL21440
Analog Specifications
V+= +5.0V. V- = GND = 0V unless otherwise specified, TA = +25°C. Boldface limits apply over the operating
temperature range, -40°C to +125°C. (Continued)
SYMBOL
PSRR
PARAMETER
Power Supply Rejection Ratio
TEST CONDITIONS
V+ = 2V to 11V
MIN
(Note 10)
MSOP Package
0.25
TDFN Package
VHYST
tPHL
tPLH
Hysteresis Input Voltage
TYP
(Note 9)
0.25
REF - 50mV
Propagation Delay - High to Low Transition CL = 100pF
Propagation Delay - Low to High Transition CL = 100pF
VOH
Output High Voltage
IO = -10mA
VOL
Output Low Voltage
IO = 3mA
MAX
(Note 10)
UNITS
1.1
mV/V
1.2
mV/V
1.5
mV/V
1.6
mV/V
REF
V
Overdrive = 10mV
100
µs
Overdrive = 100mV
50
µs
Overdrive = 10mV
200
µs
Overdrive = 100mV
100
µs
(V+) - 0.4
V
GND + 0.4
V
1.188
V
-2.0
mV
-2.5
mV
2.0
mV
2.5
mV
REFERENCE
VREF
ΔVREF
Reference Voltage
No Load
1.176
Output Load Regulation
0 ≤ ISOURCE ≤ 2mA
-0.5
0 ≤ ISINK ≤ 10µA
0.1
Analog Specifications
V+= +3.0V. V- = GND = 0V unless otherwise specified, TA = +25°C. Boldface limits apply over the operating
temperature range, -40°C to +125°C.
SYMBOL
PARAMETER
TEST CONDITIONS
MIN
(Note 10)
TYP
(Note 9)
MAX
(Note 10)
UNITS
0.40
0.7
µA
0.8
µA
±3.4
mV
±3.5
mV
±4.2
mV
±4.3
mV
1.1
nA
3
nA
(V+) - 1.5
V
5
mV/V
5.5
mV/V
7.5
mV/V
8
mV/V
V+ = 3.0V, V- = GND = 0V
ICC
Supply Current
IN+ = IN- +80mV,
HYST = REF
COMPARATOR
VOS
Input offset Voltage
VCM = 1.5V
MSOP Package
±2.3
TDFN Package
IIN
VCM
CMRR
Input Leakage Current (IN+, IN-, HYST)
VIN+ = VIN- = 1.5V
0.1
Common-Mode Input Range
Common-Mode Rejection Ratio
VV- to (V+ - 1.5V)
MSOP Package
TDFN Package
6
±2.3
1.2
1.2
FN6532.2
February 23, 2011
ISL21440
Analog Specifications
V+= +3.0V. V- = GND = 0V unless otherwise specified, TA = +25°C. Boldface limits apply over the operating
temperature range, -40°C to +125°C. (Continued)
SYMBOL
PSRR
PARAMETER
MIN
(Note 10)
TEST CONDITIONS
Power Supply Rejection Ratio
V+ = 2V to 11V
TYP
(Note 9)
MSOP Package
0.25
TDFN Package
VHYST
tPHL
tPLH
0.25
Hysteresis Input Voltage
REF - 50mV
Propagation Delay - High to Low Transition CL = 100pF
Propagation Delay - Low to High Transition CL = 100pF
VOH
Output High Voltage
IO = -6mA
VOL
Output Low Voltage
IO = 1.8mA
MAX
(Note 10)
UNITS
1.1
mV/V
1.2
mV/V
1.5
mV/V
1.6
mV/V
V
REF
Overdrive = 10mV
100
µs
Overdrive = 100mV
50
µs
Overdrive = 10mV
200
µs
Overdrive = 100mV
100
µs
(V+) - 0.4
V
GND + 0.4
V
1.188
V
-2.0
mV
-2.5
mV
2.0
mV
-2.5
mV
REFERENCE
VREF
ΔVREF
Reference Voltage
No Load
Output Load Regulation
0 ≤ ISOURCE ≤ 2mA
1.176
-0.5
0 ≤ ISINK ≤ 10µA
0.1
NOTES:
9. Over the specified temperature range. Temperature coefficient is measured by the box method whereby the change in VOUT is divided by the
temperature range; in this case, -40°C to +125°C = +165°C.
10. Parts are 100% tested at +25°C and +85°C. The -40°C and +125°C temperature limits are established by characterization and are not production
tested.
Typical Performance Curves
0.49
1.2
V+ = 5V
0.48
1.0
0.47
0.8
0.45
0.44
IDD (µA)
IDD (µA)
0.46
V+ = 3V
0.43
0.42
0.4
0.2
0.41
0.40
-40
0.6
-20
0
20
40
60
80
TEMPERATURE (°C)
FIGURE 3. IDD vs TEMPERATURE
7
100
120
0
2
3
4
5
6
7
8
9
10
11
VDD (V)
FIGURE 4. IDD vs VDD
FN6532.2
February 23, 2011
ISL21440
Typical Performance Curves
1.190
(Continued)
1.190
V+ = 3V
1.188
1.188
1.186
1.186
V+ = 5V
1.184
VREF (V)
VREF (V)
1.184
1.182
1.180
1.178
1.182
1.180
1.178
V+ = 2V
1.176
1.176
1.174
1.174
1.172
-40
-20
0
20
40
60
80
100
1.172
120
2
3
4
5
TEMPERATURE (°C)
1.183
V+ = 5V
10
11
12
1.187
1.181
V+ = 3V
1.186
VREF (V)
1.180
VREF (V)
9
1.188
1.182
1.179
1.178
1.185
1.184
1.177
V+ = 2V
1.183
1.176
0
0.5
1.0
1.5
2.0
2.5
3.0
1.182
0
0.05 0.10
0.15 0.20 0.25 0.30
LOAD (mA)
0.50
FIGURE 8. VREF vs LOAD (SINK)
1.30
3.0
NO
LOAD
1.25
10mA
LOAD
2.5
100mA
LOAD
1.20
OUTPUT (V)
2.0
1.15
1.10
1.05
1.00
1.00
0.35 0.40 0.45
LOAD (mA)
FIGURE 7. VREF vs LOAD (SOURCE)
VREF (V)
7
8
VDD (V)
FIGURE 6. VREF vs SUPPLY VOLTAGE
FIGURE 5. VREF vs TEMPERATURE
1.175
6
V+ = 3V
1.5
V+ = 5V
V+ = 2V
V+ = 11V
1.0
0.5
1.25
1.50
1.75
2.00 2.25
VDD (V)
2.50
FIGURE 9. DROPOUT - VREF OUTPUT
8
2.75
3.00
0
0
2
4
6
8
ILOAD (mA)
10
12
14
FIGURE 10. COMPARATOR OUTPUT LOW VOLTAGE vs LOAD
FN6532.2
February 23, 2011
ISL21440
Typical Performance Curves
(Continued)
12
6
10
5
4
V+ = 11V
OUTPUT (V)
OUTPUT (V)
8
V+ = 5V
6
4
V+ = 3V
2
3
2
1
V+ = 2V
0
0
5
10
15
20
25
30
ILOAD (mA)
35
40
45
0
-60 -55 -50 -45 -40 -35 -30 -25 -20 -15 -10 -5 0 5 10 15 20 25 30 35 40 45 50 55 60
IN+ - IN- (mV)
50
FIGURE 12. HYSTERESIS - 0mV (V+ = 5V)
6
6
5
5
4
4
OUTPUT (V)
OUTPUT (V)
FIGURE 11. COMPARATOR OUTPUT HIGH VOLTAGE vs LOAD
3
2
3
2
1
1
0
-60-55 -50 -45 -40 -35 -30 -25 -20 -15 -10 -5 0 5 10 15 20 25 30 35 40 45 50 55 60
0
-60-55 -50 -45 -40 -35 -30 -25 -20 -15 -10 -5 0 5 10 15 20 25 30 35 40 45 50 55 60
IN+ - IN- (mV)
IN+ - IN- (mV)
FIGURE 14. HYSTERESIS - 25mV (V+ = 5V)
6
6
5
5
4
4
OUTPUT (V)
OUTPUT (V)
FIGURE 13. HYSTERESIS - 12.5mV (V+ = 5V)
3
2
3
2
1
1
0
-60-55-50-45-40-35-30-25-20-15-10 -5 0 5 10 15 20 25 30 35 40 45 50 55 60
IN+ - IN- (mV)
0
-60-55-50-45-40-35-30-25-20-15-10 -5 0 5 10 15 20 25 30 35 40 45 50 55 60
IN+ - IN- (mV)
FIGURE 15. HYSTERESIS - 37.5mV (V+ = 5V)
9
FIGURE 16. HYSTERESIS - 50mV (V+ = 5V)
FN6532.2
February 23, 2011
ISL21440
(Continued)
3.5
3.5
3.0
3.0
2.5
2.5
OUTPUT (V)
OUTPUT (V)
Typical Performance Curves
2.0
1.5
2.0
1.5
1.0
1.0
0.5
0.5
0
-60-55-50-45-40-35-30-25-20-15-10 -5 0 5 10 15 20 25 30 35 40 45 50 55 60
IN+ - IN- (mV)
0
-60-55-50-45-40-35-30-25-20-15-10 -5 0 5 10 15 20 25 30 35 40 45 50 55 60
IN+ - IN- (mV)
FIGURE 18. HYSTERESIS - 12.5mV (V+ = 3V)
3.5
3.5
3.0
3.0
2.5
2.5
OUTPUT (V)
OUTPUT (V)
FIGURE 17. HYSTERESIS - 0mV (V+ = 3V)
2.0
1.5
2.0
1.5
1.0
1.0
0.5
0.5
0
-60-55-50-45-40-35-30-25-20-15-10 -5 0 5 10 15 20 25 30 35 40 45 50 55 60
IN+ - IN- (mV)
0
-60-55-50-45-40-35-30-25-20-15-10 -5 0 5 10 15 20 25 30 35 40 45 50 55 60
IN+ - IN- (mV)
FIGURE 20. HYSTERESIS - 37.5mV (V+ = 3V)
3.5
90
3.0
80
2.5
70
2.0
60
TIME (µs)
OUTPUT (V)
FIGURE 19. HYSTERESIS - 25mV (V+ = 3V)
1.5
50
1.0
40
0.5
30
0
-60-55-50-45-40-35-30-25-20-15-10 -5 0 5 10 15 20 25 30 35 40 45 50 55 60
IN+ - IN- (mV)
FIGURE 21. HYSTERESIS - 50mV (V+ = 3V)
10
3V
20
10
5V
20
30
40
50
60
70
80
90
INPUT VOLTAGE (mV)
100 110
120
FIGURE 22. OUTPUT RESPONSE TIME vs INPUT OVERDRIVE
(tPHL)
FN6532.2
February 23, 2011
ISL21440
Typical Performance Curves
(Continued)
270
5.5
245
5.0
220
4.5
4.0
3.5
170
3V
3.0
OUTPUT (V)
TIME (µs)
195
145
120
95
2.5
20
10
V+
1.5
1.0
70
45
OUT
2.0
0.5
5V
20
0
30
40
50
60
70
80
90
100
110
-0.5
0
120
0.2
0.4
0.6
INPUT VOLTAGE (mV)
0.8
1.0
1.2
1.4
1.6
1.8
2.0
TIME (ms)
FIGURE 23. OUTPUT RESPONSE TIME vs INPUT OVERDRIVE
(tPLH)
FIGURE 24. POWER-UP/DOWN OUTPUT RESPONSE
(V+ = 5V, IN+ = V+, IN- = VREF)
3.5
3.0
OUTPUT (V)
2.5
2.0
OUT
1.5
V+
1.0
0.5
0
-0.5
0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
TIME (ms)
FIGURE 25. POWER-UP/DOWN OUTPUT RESPONSE (V+ = 3V, IN+ = V+, IN- = VREF)
Functional Description
Device Power
The ISL21440 device has a single positive supply pin, V+, and
two other supply pins, V- and GND. Normally for single supply
applications the V- pin is tied to system ground as well as the
GND pin. The separate ground pin allows the comparator to be
powered by split supplies from ±1.0V to ±5.5V. Note that the
minimum supply voltage will be 0.8V above the comparator
maximum input level for accurate operation.
Comparator Section
The comparator inputs can swing from the negative supply (GND
pin) to within 0.8V of the positive supply (V+). Alternatively, with
the comparator input set at the 1.182V reference level, the
minimum input voltage for accurate operation is 2.0V. If the
inputs are expected to see voltage levels above V+ or below
ground, they should be clamped with low leakage Schottky
diodes.
The CMOS output swings essentially from the GND potential to
V+ potential, depending on load current. If loads in excess of
11
1mA are expected, then a 0.1µF decoupling capacitor at the V+
pin should be added.
Voltage Reference Section
The voltage reference is a micropower FGA reference and is set
to 1.182V ±0.5% at the factory. The reference output can source
up to 2mA but the sink capability is very limited at only 10µA,
maximum. Small value capacitors, up to 10nF, can be used on
the reference output to lower noise if desired.
Applications Information
Handling and Board Mounting
FGA references provide excellent initial accuracy and low
temperature drift at the expense of very little power drain. There
are some precautions to take to insure this accuracy is not
compromised. Excessive heat during solder reflow can cause
excessive initial accuracy drift, so the recommended +260°C
max temperature profile should not be exceeded. Expect up to
1mV drift from the solder reflow process.
FGA references are susceptible to excessive X-radiation like that
used in PC board manufacturing. Initial accuracy can change
FN6532.2
February 23, 2011
ISL21440
10mV or more under extreme radiation. If an assembled board
needs to be X-rayed, care should be taken to shield the FGA
reference device.
Hysteresis
The Hysteresis function allows for changing the value of the
reference switchover point depending on the previous state of
the comparator. This works to remove the effects of noise or
glitches in the voltage detection input and provide more reliable
output transitions.
Hysteresis is added to the ISL21440 by connecting one resistor
between the REF and HYST pins (RREF), and another
resistor(RHYST) between the HYST pin and ground. The hysteresis
voltage (VH) is designed to be twice the voltage difference
between the HYST pin and REF pin (VH = 2 * (VREF - VHYST)).
Since the reference voltage is 1.182V (VREF), Equations 1 and 2
for these two resistors are shown as follows:
R REF = V H ⁄ ( 2∗ I REF ) = ( V REF – V HYST ) ⁄ I REF
(EQ. 1)
R HYST = ( 1.182 – V H ⁄ 2 ) ⁄ I REF = V HYST ⁄ I REF
(EQ. 2)
the received dose by over 90%. The lead frame for the device
which is on the bottom also provides similar shielding.
If a device is expected to pass through luggage X-ray machines
numerous times, it is advised to mount a 2-layer (minimum) PC
board over the top of the package, which along with a ground
plane underneath will effectively shield it from 50 to 100 passes
through the machine. Since these machines vary in X-ray dose
delivered, it is difficult to produce an accurate maximum pass
recommendation.
Typical Applications
Low Battery Detector
Figure 26 shows a typical implementation for the ISL21440, a
low battery detector. The values for RREF and RHYST provide
20mV of hysteresis and 0.5µA IREF. The input trip point for
Vdetect is the same as the reference voltage, 1.182V, and a
resistor divider at the input sets the LoBAT trip point at 2.7V. The
total current draw for the circuit is going to be 1.1µA for VDD and
0.6µA for VBAT.
IREF is chosen to be less than the maximum output of the
reference, usually 5µA is a safe value but for lowest power, 0.1µA
can be used.
2.4M
1.8M
20k
Board Assembly Considerations
Post-assembly X-ray inspection may also lead to permanent
changes in device output voltage and should be minimized or
avoided. If X-ray inspection is required, it is advisable to monitor
the reference output voltage to verify excessive shift has not
occurred. If large amounts of shift are observed, it is best to add
an X-ray shield consisting of thin zinc (300µm) sheeting to allow
clear imaging, yet block x-ray energy that affects the FGA
reference.
Special Applications Considerations
In addition to post-assembly examination, there are also other
X-ray sources that may affect the FGA reference long term
accuracy. Airport screening machines contain X-rays and will
have a cumulative effect on the voltage reference output
accuracy. Carry-on luggage screening uses low level X-rays and is
not a major source of output voltage shift, although if a product
is expected to pass through that type of screening over 100x it
may need to consider shielding with copper or aluminum.
Checked luggage X-rays are higher intensity and can cause
output voltage shift in much fewer passes, so devices expected to
go through those machines should definitely consider shielding.
Note that just two layers of 1/2 ounce copper planes will reduce
12
V+
IN+
IN-
If the hysteresis is not used, the HYST pin should be tied to the
REF pin.
FGA references provide high accuracy and low temperature drift
but some PC board assembly precautions are necessary. Normal
Output voltage shifts of 100µV to 1mV can be expected with
Pb-free reflow profiles or wave solder on multi-layer FR4 PC
boards. Precautions should be taken to avoid excessive heat or
extended exposure to high reflow or wave solder temperatures,
this may reduce device initial accuracy.
VDD
VBAT
+
OUT
LoBAT-
-
HYST
REF
ISL21440
2.4M
V-
GND
FIGURE 26. LOW BATTERY DETECTOR WITH HYSTERESIS
Window Comparator
The ISL21440 can be combined with a micropower comparator
to produce a window comparator circuit. The circuit in Figure 27
uses a 3 resistor divider to produce high and low trip points, and
the ISL28197 (800nA supply current) comparator is added to
give the second output. The two outputs can be used separately
for over or undervoltage indication, or a gate can be added as
shown to report either in-window or out-of window condition.
The resistors are shown as Equations 3, 4 and 5 as follows.
Set:
R 3 = 1M ( 1% )
(EQ. 3)
R2 = R3 [ VH ⁄ VL – 1 ]
(EQ. 4)
R 1 = R 3 ( [ V H ⁄ V REF – 1 ] – R 2 )
(EQ. 5)
Example: For VH = 3.8V, VL = 2.7V (3.3V ± 0.5V)
R2 = 402k, R1 = 1.82M (can be 1%)
The resulting circuit draws about 3µA and works down to VDD =
2.2V.
FN6532.2
February 23, 2011
ISL21440
V BAT
R1
V BAT OR V DD
IN+
IN-
R2
V+
+
-
OUT
V WINDOW
HYST
REF
ISL21440
V-
+
R3
V LOW -
V HI-
GND
ISL28197
FIGURE 27. WINDOW COMPARATOR CIRCUIT
13
FN6532.2
February 23, 2011
ISL21440
Revision History
The revision history provided is for informational purposes only and is believed to be accurate, but not warranted. Please go to web to make
sure you have the latest Rev.
DATE
REVISION
1/24/11
FN6532.2
CHANGE
On page 3:
Updated Tape & Reel note in “Ordering Information” to add new standard "Add “-T*” suffix for tape and reel."
The "*" covers all possible tape and reel options
On page 6:
Separated “Analog Specifications” tables into 2 tables. Put specs from "V+ = 3.0V, V- = GND = 0V" to end of table
into separate table and added following common conditions:
"V+= +3.0V. V- = GND = 0V unless otherwise specified, TA = +25°C. Boldface limits apply over the operating
temperature range, -40°C to +125°C."
On page 6:
Changed conditions for “VOH” from Io = -7mA to Io = -6mA
Changed conditions for “VOL” from Io = 3mA to Io = 1.8mA
3/31/10
In “Window Comparator” on page 12, changed "with a micropower to.." to: "with a micropower comparator to.."
Page 14, replaced POD M8.118 with newest revision. Updated to new intersil format by adding land pattern and
moving dimensions from table onto drawing
3/2/10
FN6532.1
Updated datasheet with the TDFN spec.
Spec added on pages 5-6 are: VOS, IIN, CMRR and PSRR. Each spec has an added row for the TDFN package
and the original limit for the MSOP package.
12/7/09
FN6532.0
Initial Release
Products
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address some of the industry's fastest growing markets, such as, flat panel displays, cell phones, handheld products, and notebooks.
Intersil's product families address power management and analog signal processing functions. Go to www.intersil.com/products for a
complete list of Intersil product families.
*For a complete listing of Applications, Related Documentation and Related Parts, please see the respective device information page
on intersil.com: ISL21440
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FITs are available from our website at http://rel.intersil.com/reports/search.php
14
FN6532.2
February 23, 2011
ISL21440
Package Outline Drawing
M8.118
8 LEAD MINI SMALL OUTLINE PLASTIC PACKAGE
Rev 3, 3/10
5
3.0±0.05
A
DETAIL "X"
D
8
1.10 MAX
SIDE VIEW 2
0.09 - 0.20
4.9±0.15
3.0±0.05
5
0.95 REF
PIN# 1 ID
1
2
B
0.65 BSC
GAUGE
PLANE
TOP VIEW
0.55 ± 0.15
0.25
3°±3°
0.85±010
H
DETAIL "X"
C
SEATING PLANE
0.25 - 0.036
0.08 M C A-B D
0.10 ± 0.05
0.10 C
SIDE VIEW 1
(5.80)
NOTES:
(4.40)
(3.00)
1. Dimensions are in millimeters.
(0.65)
(0.40)
(1.40)
TYPICAL RECOMMENDED LAND PATTERN
15
2. Dimensioning and tolerancing conform to JEDEC MO-187-AA
and AMSEY14.5m-1994.
3. Plastic or metal protrusions of 0.15mm max per side are not
included.
4. Plastic interlead protrusions of 0.15mm max per side are not
included.
5. Dimensions are measured at Datum Plane "H".
6. Dimensions in ( ) are for reference only.
FN6532.2
February 23, 2011
ISL21440
Package Outline Drawing
L8.3x3G
8 LEAD THIN DUAL FLAT NO-LEAD PLASTIC PACKAGE (TDFN)
Rev 0, 5/07
PIN 1 INDEX AREA
3.00
B
1.45
A
PIN 1 INDEX AREA
0.075 C
4X
6X 0.50 BSC
3.00
1.50
REF
1.75
8X 0.25
0.10 M C A B
8X 0.40
2.20
TOP VIEW
BOTTOM VIEW
SEE DETAIL X''
(8X 0.60)
(8X 0.25)
0.10 C
0.75
C
(1.75)
SEATING PLANE
0.08 C
(6X 0.50 BSC)
SIDE VIEW
(1.45)
(2.20)
TYPICAL RECOMMENDED LAND PATTERN
c
0.20 REF
5
0~0.05
DETAIL “X”
NOTES:
1. Controlling dimensions are in mm.
Dimensions in ( ) for reference only.
2. Unless otherwise specified, tolerance : Decimal ±0.05
Angular ±2°
3. Dimensioning and tolerancing conform to JEDEC STD MO220-D.
4. The configuration of the pin #1 identifier is optional, but must be located
within the zone indicated. The pin #1 identifier may be either a mold or
mark feature.
5. Tiebar shown (if present) is a non-functional feature.
For additional products, see www.intersil.com/product_tree
Intersil products are manufactured, assembled and tested utilizing ISO9000 quality systems as noted
in the quality certifications found 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
16
FN6532.2
February 23, 2011