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LTC1540 Nanopower Comparator with Reference
FEATURES
s s s s s s s s s s s
DESCRIPTION
The LTC (R)1540 is an ultralow power, single comparator with built-in reference. The comparator's features include less than 0.6A supply current over the commercial temperature range, a 1.182V 2% reference, programmable hysteresis and TTL/CMOS outputs that sink and source current. The reference output can drive a bypass capacitor of up to 0.01F without oscillation. The comparator operates from a single 2V to 11V supply or a dual 1V to 5.5V supply. Comparator hysteresis is easily programmed by using two resistors and the HYST pin. Each comparator's input operates from the negative supply to within 1.3V of the positive supply. The comparator output stage can continuously source up to 40mA. By eliminating the cross-conducting current that normally occur when the comparator changes logic states, power supply glitches are eliminated. The LTC1540 is available in the 8-pin MSOP and SO packages.
, LTC and LT are registered trademarks of Linear Technology Corporation.
Ultralow Quiescent Current: 0.3A Typ Reference Output Drives 0.01F Capacitor Adjustable Hysteresis Wide Supply Range: 2V to 11V Input Voltage Range Includes the Negative Supply Reference Output Sources Up to 1mA TTL/CMOS Compatible Outputs 60s Propagation Delay with 10mV Overdrive No Crowbar Current 40mA Continuous Source Current Pin Compatible with LTC1440, MAX921, MAX931
APPLICATIONS
s s s s
Battery-Powered System Monitoring Threshold Detectors Window Comparators Oscillator Circuits
TYPICAL APPLICATION
Nanopower 2.9V VCC Threshold Detector
3.3V
0.50
LTC1540 Supply Current vs Temperature
R1 4.32M 1% R2 3M 1%
7 V 3 IN +
+
LTC1540
SUPPLY CURRENT (A)
0.45 0.40 0.35 0.30 0.25 0.20
V + = 5V V - = GND = 0V
+
8 OUT
4 IN-
-
5 HYST
6 REF
V- 2
GND 1
1540 * TA01
0.15 -40 -20
U
U
U
40 20 60 0 TEMPERATURE (C)
80
100
1540 * TA02
1
LTC1540
ABSOLUTE MAXIMUM RATINGS
Voltage V + to V -, V + to GND, GND to V - ...........12V to - 0.3V IN +, IN -, HYST ................. (V + + 0.3V) to (V - - 0.3V) REF ................................... (V + + 0.3V) to (V - - 0.3V) OUT ............................... (V + + 0.3V) to (GND - 0.3V) Current IN +, IN -, HYST ................................................. 20mA REF ................................................................... 20mA OUT .................................................................. 50mA OUT Short-Circuit Duration (V + 5.5V) ...... Continuous Power Dissipation ............................................. 500mW Operating Temperature Range LTC1540C............................................... 0C to 70C LTC1540I ............................................ - 40C to 85C Storage Temperature Range ................ - 65C to 150C Lead Temperature (Soldering, 10 sec).................. 300C
PACKAGE/ORDER INFORMATION
TOP VIEW GND 1 V- 2 IN + 3 8 7 6 5 OUT V+ REF HYST
ORDER PART NUMBER LTC1540CS8 LTC1540IS8 S8 PART MARKING 1540 1540I
GND V- IN + IN - 1 2 3 4
IN - 4
S8 PACKAGE 8-LEAD PLASTIC SO TJMAX = 125C, JA = 175C/ W
Consult factory for Military grade parts.
ELECTRICAL CHARACTERISTICS
SYMBOL PARAMETER Power Supply V+ ICC Supply Voltage Range Supply Current CONDITIONS
V + = 5V, V - = GND = 0V, TA = 25C unless otherwise noted.
MIN
q
= 80mV, HYST = REF, C-Grade IN + = IN - = 80mV, HYST = REF, I-Grade VCM = 2.5V LTC1540CMS8
IN + = IN -
Comparator VOS Comparator Input Offset Voltage
q q q q q
IIN VCM CMRR PSRR VHYST tPD VOH VOL
Input Leakage Current (IN +, IN -) Input Leakage Current (HYST) Comparator Input Common Mode Range Common Mode Rejection Ratio Power Supply Rejection Ratio Hysteresis Input Voltage Range Propagation Delay Output High Voltage Output Low Voltage
VIN + = VIN - = 2.5V
V-
to V +
- 1.3V
q REF - 50mV
V + = 2V to 11V COUT = 100pF IO = - 13mA IO = 1.8mA Overdrive = 10mV Overdrive = 100mV
q q
2
U
U
W
WW U
W
TOP VIEW 8 7 6 5 OUT V+ REF HYST
ORDER PART NUMBER LTC1540CMS8 MS8 PART MARKING LTCE
MS8 PACKAGE 8-LEAD PLASTIC MSOP TJMAX = 125C, JA = 250C/ W
TYP
MAX 11.0
UNITS V A A mV mV mV nA nA V mV/V mV/V V s s V
2.0 0.3
q q
0.68 0.71 12 15 16
0.01 0.02 V- 0.1 0.1 60 50 V + - 0.4V
1.0 1.0 V + - 1.3V 1 1 REF
GND + 0.4V
V
LTC1540
ELECTRICAL CHARACTERISTICS
SYMBOL PARAMETER Reference Reference Voltage VREF CONDITIONS
V + = 5V, V - = GND = 0V, TA = 25C unless otherwise noted.
MIN Commercial Temp Range Industrial Temp Range
q q q q q
TYP 1.182 1.182 1.182 0.5 0.5
MAX 1.206 1.212 1.208 2.5 1.5 5
UNITS V V V mV mV mV
(SO-8) No Load LTC1540CMS8 0 ISOURCE 1mA 0 ISINK 10A
1.158 1.152 1.156
VREF
Load Regulation
V + = 3V, V - = GND = 0V, TA = 25C unless otherwise noted. SYMBOL PARAMETER Power Supply V+ ICC Supply Voltage Range Supply Current IN + = IN - = 80mV, HYST = REF, C-Grade IN + = IN - = 80mV, HYST = REF, I-Grade VCM = 2.5V LTC1540CMS8 IIN VCM CMRR PSRR VHYST tPD VOH VOL Reference VREF Reference Voltage (SO-8) No Load LTC1540CMS8 VREF Load Regulation 0 ISOURCE 1mA 0 ISINK 10A
q q q q q q q q q
CONDITIONS
MIN 2
TYP
MAX 11
UNITS V A A mV mV mV nA nA V mV/V mV/V V s s V
0.28
0.61 0.64 12 15 16
Comparator VOS Comparator Input Offset Voltage
Input Leakage Current (IN +, IN -) Input Leakage Current (HYST) Comparator Input Common Mode Range Common Mode Rejection Ratio Power Supply Rejection Ratio Hysteresis Input Voltage Range Propagation Delay Output High Voltage Output Low Voltage
VIN + = VIN - = 1.5V
0.01 0.02 V- 0.1 0.1
1 1 V + - 1.3V 1 1 REF
V-
to V +
- 1.3V
q REF - 50mV
V + = 2V to 11V COUT = 100pF IO = - 8mA IO = 0.8mA Commercial Temp Range Industrial Temp Range Overdrive = 10mV Overdrive = 100mV
q q
70 60 V + - 0.4V GND + 0.4V 1.158 1.152 1.156 1.182 1.182 1.182 0.75 0.5 1.206 1.212 1.208 3.5 1.5 5
V V V V mV mV mV
q q q q
The q denotes specifications which apply over the full operating temperature range.
Note 1: MS8 package devices are designed for and intended to meet commercial temperature range specifications but are not tested at 0C.
3
LTC1540 TYPICAL PERFORMANCE CHARACTERISTICS
Supply Current vs Temperature
0.5 V + = 5V V - = GND = 0V
REFERENCE VOLTAGE (V)
0.4
SUPPLY CURRENT (A)
V + = 3V V - = GND = 0V
0.3 V + = 2V V - = GND = 0V
VREF (mV)
0.2
0.1
0 - 60 - 40 -20 0 20 40 60 TEMPERATURE (C)
Reference Voltage Load Regulation (Source)
5 V + = 5V V - = GND = 0V TA = 25C
OUTPUT VOLTAGE (V)
4
OUTPUT VOLTAGE (V)
VREF (mV)
3
2
1
0 0 3 2 1 OUTPUT SOURCE CURRENT (mA) 4
1540 G04
Comparator Short-Circuit Current vs Supply Voltage
200 180 160 140
CURRENT (mA)
TA = 25C OUTPUT CONNECTED TO - V = GND = 0V; SOURCE CURRENT OUTPUT CONNECTED TO V +; SINK CURRENT
DIFFERENTIAL INPUT VOLTAGE (V)
TIME (s)
120 100 80 60 40 20 0 0
1
2
345678 SUPPLY VOLTAGE (V)
4
UW
80
1540 G01
Reference Voltage vs Temperature
1.190 1.188 1.186 1.184 1.182 1.180 1.178 1.176 1.174 V + = 5V V - = GND = 0V
10 9 8 7 6 5 4 3 2 1 0
Reference Voltage Load Regulation (Sink)
V + = 5V V - = GND = 0V TA = 25C
100
1.172 20 40 60 - 60 - 40 - 20 0 TEMPERATURE (C)
80
100
0
5
10 15 20 25 30 35 OUTPUT SINK CURRENT (A)
40
1540 G02
1540 G03
Comparator Output Voltage (High) vs Load Current
5 TA = 25C V+ = 5V 4 2.0 2.5
Comparator Output Voltage (Low) vs Load Current
TA = 25C V+ = 3V V+ = 2V V+ = 5V
3 V+ = 3V
1.5
2
1.0
1
V+ = 2V
0.5
0 0 10 20 30 40 50 60 LOAD CURRENT (mA) 70 80
0 0 10 20 30 40 50 60 LOAD CURRENT (mA) 70 80
1540 G05
1540 G06
Comparator Response Time vs Input Overdrive
80 TA = 25C 75 V + = 5V V - = GND = 0V 70 65 60 55 50 45 40 35 30 tPHL tPLH
Hysteresis Control
80 60 40 20 0 - 20 - 40 - 60 - 80 0 10 20 30 VREF - VHYST (mV) 40 50
1540 G09
9
10
10 20 30 40 50 60 70 80 90 100 110 INPUT VOLTAGE (mV)
1540 G08
1540 G07
LTC1540
PIN FUNCTIONS
GND (Pin 1): Ground. Connect to V - for single supply operation. V - (Pin 2): Negative Supply. Potential should be more negative than GND. Connect to ground for single supply operation. IN + (Pin 3): Noninverting Comparator Input. Input common mode range from V - to V + - 1.3V. Input current typically 10pA at 25C. IN - (Pin 4): Inverting Comparator Input. Input common mode range from V - to V + - 1.3V. Input current typically 10pA at 25C. HYST (Pin 5): Hysteresis Input. Connect to REF if not used. Input voltage range is from VREF to VREF - 50mV. REF (Pin 6): Reference Output. 1.182V with respect to V -. Can source up to 1mA and sink 10A at 25C. Drive 0.01F bypass capacitor without oscillation. V + (Pin 7): Positive Supply operating voltage is from 2V to 11V. OUT (Pin 8): Comparator CMOS Output. Swings from GND to V +. Output can source up to 40mA and sink 5mA.
APPLICATIONS INFORMATION
The LTC1540 is a nanopower comparator with a built-in 1.182V reference. Features include programmable hysteresis, wide supply voltage range (2V to 11V) and the ability of the reference to drive up to a 0.01F capacitor without oscillation. The comparator's CMOS outputs can source up to 40mA while supply current glitches that normally occur when switching logic states, have been eliminated. Power Supplies The comparator operates from a single 2V to 11V supply. The LTC1540 includes a separate ground for the comparator output stage, allowing a split supply ranging from 1V to 5.5V. Connecting V - to GND will allow single supply operation. If the comparator output is required to source more than 1mA, or the supply source impedance is high, V + should be bypassed with a 0.1F capacitor. Comparator Inputs The comparator inputs can swing from the negative supply, V -, to within 1.3V (max) of the positive supply V+. The inputs can be forced 300mV below V- or above V+ without damage and the typical input leakage current is only 10pA. Comparator Output The comparator output swings between GND and V + to assure TTL compatibility with a split supply. The output is capable of sourcing up to 40mA and sinking up to 5mA while still maintaining nanoampere quiescent currents. The output stage does not generate crowbar switching currents during transitions which helps minimize parasitic feedback through the supply pins. Voltage Reference The internal bandgap reference has a voltage of 1.182V referenced to V -. The reference accuracy is 2.0% from 0C to 70C. It can source up to 1mA and sink up to 10A with a 5V supply. The reference can drive a bypass capacitor of up to 0.01F without oscillation and by inserting a series resistor, capacitance values up to 10F can be used (Figure 1). Figure 2 shows the resistor value required for different capacitor values to achieve critical damping. Bypassing the reference can help prevent false tripping of the comparators by preventing glitches on V + or reference load transients from disturbing the reference output voltage.
U
W
U
U
U
U
U
1
GND
LTC1540
OUT 8 7
- 2V
V+
+
3 IN+
- 4 IN
-
REF 6 5
HYST
1540 * PD
5
LTC1540
APPLICATIONS INFORMATION
REFERENCE OUTPUT REF R1 LTC1540
C1
V-
1540 * F01
Figure 1. Damping the Reference Output
R3 2.4M
1000
RESISTOR VALUE (k)
100
10
1
0.1 0.001
0.01 0.1 1 CAPACITOR VALUE (F)
10
1540 * F02
2mV/DIV
Figure 2. Damping Resistance vs Bypass Capacitor Value
Figure 3 shows the bypassed reference output with a square wave applied to the V + pin. Resistors R2 and R3 set 10mV of hysteresis voltage band while R1 damps the reference response. Note that the comparator output doesn't trip. Low Voltage Operation: V + = 1.6V The guaranteed minimum operating voltage is 2V (or 1V). As the total supply voltage is reduced below 2V, the performance degrades and the supply current falls. At low supply voltages, the comparator's output drive is reduced and the propagation delay increases. The VREF and VOS are also slightly worse. The useful input voltage range extends from the negative supply to 0.9V below the positive supply. Test your prototype over the full temperature and supply voltage range if operation below 2V is anticipated. Because of the increase in supply current, operation below 1.5V is not recommended (Figure 4).
SUPPLY CURRENT (A)
6
U
W
U
U
7 V+ 3 IN + LTC1540 8 4 IN- 5V TO 8V
+
OUT
-
5 HYST R2 10k R1 430 C1 1F
6 REF
V- 2
GND 1
1540 * F03a
Figure 3a. Power Supply Transient Test Circuit
8V V+ 5V VREF
OUT 2ms/DIV
1540 F03b
Figure 3b. Power Supply Transient Rejection
5
4
V - = GND = 0V IN+ = 0V IN - = REF = HYST TA = 25C
3
2
1
0
0
0.5
1.5 2.0 1.0 SUPPLY VOLTAGE (V)
2.5
1540 F04
Figure 4. Supply Current vs Supply Voltage
LTC1540
APPLICATIONS INFORMATION
Hysteresis Hysteresis can be added to the LTC1540 by connecting a resistor (R1) between the REF and HYST pins and a second resistor (R2) from HYST to V - (Figure 5). The difference between the upper and lower threshold voltages, or hysteresis voltage band (VHB), is equal to twice the voltage difference between the REF and HYST pins. When more hysteresis is added, the upper threshold increases the same amount as the low threshold decreases. The maximum voltage allowed between REF and HYST pins is 50mV, producing a maximum hysteresis voltage band of 100mV. The hysteresis band may vary by up to 15%. If hysteresis is not wanted, the HYST pin should be shorted to REF. Acceptable values for IREF range from 0.1A to 5A. If 2.4M is chosen for R2, then the value of R1 (k) is equal to the value of VHB (mV).
IREF R1 5 R2 HYST V- 2 6 REF LTC1540 R2 = R1 = VHB (2)(IREF)
TYPICAL APPLICATIONS
Level Detector The LTC1540 is ideal for use as a nanopower level detector as shown in Figure 6. R1 and R2 form a voltage divider from VIN to the noninverting comparator input. R3 and R4 set the hysteresis voltage, and R5 and C1 bypass the reference output. The following design procedure can be used to select the component values: 1. Choose the VIN voltage trip level, in this example 4.65V. 2. Calculate the required resistive divider ratio. Ratio = VREF/ VIN Ratio = 1.182V/4.65V = 0.254 3. Choose the required hysteresis voltage band at the input VHBIN, in this example 60mV. Calculate the hysteresis voltage band referred to the comparator input VHB. VHB = (VHBIN)(Ratio) VHB = (60mV)(0.254) VHB = 15.24mV 4. Choose the values for R3 and R4 to set the hysteresis. R4 = 2.4M R3 (k) = 15k, VHB (mV) = 15mV 5. Choose the values for R1 and R2 to set the trip point.
R3 15k 1% R4 2.4M 1% R5 430 5% C1 1F
U
W
U
U
U
(
1.182V - IREF
VHB 2
)
1540 * F05
Figure 5. Programmable Hysteresis
R1 =
VREF 1.182V = = 1.18M IBIAS 1A VIN V VREF + HB 2 -1
R2 = R1
4.65V -1 R2 = 1.18M 15mV 1.182V + 2 R2 = 3.40M
VIN R2 3.4M 1% R1 1.18M 1% 5V 7 V+ 3 IN + LTC1540
+
8 OUT
4 IN-
-
5 HYST
6 REF
V- 2
GND 1
1540 F06
Figure 6. Glitch-Free Level Detector with Hysteresis
7
LTC1540
TYPICAL APPLICATIONS
3.3V Output Low Dropout Linear Regulator The LTC1540 can be connected as a micropower (IQ = 5.5A at VIN = 5V) low dropout linear regulator (Figure 7). When the output is low, Q1 turns on, allowing current to charge output capacitor C1. Local feedback formed by R4, Q1 and Q2 creates a constant-current source from the 5V input to C1. R4, R1 and Q2's VBE also provide current limiting in the case of an output short-circuit to ground. C2 reduces output ripple, while the R2-R3 feedback voltage divider establishes the output voltage. Auto Power-Off Source Figure 8 shows the circuit for a 30mA power supply that has a timed auto power-off function. The comparator
V IN = 5V R4 10 Q1 TP0610L V OUT 3.3V
432k LTC1540 V+
7 V+ 3 IN + LTC1540
Q2 2N3906 R1 47k
+
OUT 8
4 IN-
-
R3 750k 1% R2 430k 1%
5 HYST C2 2.2nF
2M
6 REF C3 GND 1 V- 2
1540 F07
Figure 7. 3.3V Output Low Dropout Linear Regulator
8
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output is the switched power supply output. With a 10mA load, it typically provides a voltage of (VBAT - 0.17V). The whole circuit draws a mere 0.8A of quiescent current with VBAT = 5V. The three resistor voltage divider programs 50mV of hysteresis for the comparator, and sets the IN - voltage at 200mV. This gives an IN + trip threshold of approximately 150mV The RC time constant determines the maximum power-on time of the OUT pin before power down occurs. This period can be approximated by: t = 4.6RC (seconds) The actual time will vary with both the leakage current of the capacitor and the input current at the IN + pin.
V BAT
7 IN + 3
MOMENTARY SWITCH
C
R
C1 10F
+
OUT 8 4 IN - (VBAT - 0.17V) 10mA
-
5 HYST 121k 6 REF
V- 2
GND 1
1540 F08
Figure 8. Auto Power-Off Switch Operates on 0.8A Quiescent Current
LTC1540
TYPICAL APPLICATIONS
Low-Battery Detect Figure 9 shows how to use the LTC1540 for a low-battery detect, drawing only 1.4A at VBAT = 2V. The circuit is powered by a 2-cell NiCd battery. The VBAT pin could be as low as 1.6V when the batteries are completely depleted. The electrical specifications of the LTC1540 guarantee operation down to a supply voltage of 2V, but it is still functional with the supply as low as 1.6V. Some parameters, such as VREF and VOS, will be degraded on lower supply voltages. The input voltage range extends from 0.9V below the positive supply to the negative supply.
U
VBAT = ~1.6V TO 2.5V R1 3M R2 1.1M 7 V+ 3 IN + LTC1540 OUT 4 IN
-
2-CELL NiCd
+
8 LBO
-
6 REF R3 40k R4 1.2M R5 1M
5 HYST
V- 2
GND 1
1540 F09
Figure 9. Low-Battery Detect Works Down to 1.6V
9
LTC1540
PACKAGE DESCRIPTION
0.007 (0.18) 0.021 0.006 (0.53 0.015)
* DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS. MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE ** DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS. INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE
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Dimensions in inches (millimeters) unless otherwise noted.
MS8 Package 8-Lead Plastic MSOP
(LTC DWG # 05-08-1660)
0.118 0.004* (3.00 0.102) 8 76 5
0.192 0.004 (4.88 0.10)
0.118 0.004** (3.00 0.102)
1 0.040 0.006 (1.02 0.15) 0 - 6 TYP SEATING PLANE 0.012 (0.30) 0.0256 REF (0.65) TYP
23
4 0.034 0.004 (0.86 0.102)
0.006 0.004 (0.15 0.102)
MSOP (MS8) 1197
LTC1540
PACKAGE DESCRIPTION
0.010 - 0.020 x 45 (0.254 - 0.508) 0.008 - 0.010 (0.203 - 0.254) 0- 8 TYP
0.016 - 0.050 0.406 - 1.270
*DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE **DIMENSION DOES NOT INCLUDE INTERLEAD FLASH. INTERLEAD FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE
Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
U
Dimensions in inches (millimeters) unless otherwise noted.
S8 Package 8-Lead Plastic Small Outline (Narrow 0.150)
(LTC DWG # 05-08-1610)
0.189 - 0.197* (4.801 - 5.004) 8 7 6 5
0.228 - 0.244 (5.791 - 6.197)
0.150 - 0.157** (3.810 - 3.988)
1 0.053 - 0.069 (1.346 - 1.752)
2
3
4
0.004 - 0.010 (0.101 - 0.254)
0.014 - 0.019 (0.355 - 0.483)
0.050 (1.270) TYP
SO8 0996
11
LTC1540
TYPICAL APPLICATION
RF Field Detector Figure 10 shows the complete circuit for a field detector which was tested at 445MHz. A transmission line is used to match the detector diode (1N5712) to a quarter-wave whip antenna. The 0.23 wavelength transmission line section transforms the 1pF (350) diode junction capacitance to a virtual short at the base of the antenna. At the same time it converts the received antenna current to a voltage loop at the diode, giving excellent sensitivity. The rectified output is monitored by the LTC1540 comparator. The internal reference is used to set up a threshold of about 18mV at the inverting input. A rising edge at the comparator output triggers a one shot that temporarily enables answer back and any other pulsed functions. The total supply current is 400nA. Among other monolithic one shots, the CD4047 draws the least amount of transient current.
/4 FB 10k 10nF 4 0.23 10nF 1N5712 180k 12M 3 5 6
RELATED PARTS
PART NUMBER LT 1178/LT1179 LT1351 LT1352/LT1353 LTC1440 LTC1443/LTC1444/LTC1445 LTC1474 LT1495 LT1521 LT1634
(R)
DESCRIPTION Dual/Quad 17A Precision Single Supply Op Amps Single 250A, 3MHz, 200V/s Op Amp with Shutdown Dual/Quad 250A, 3MHz, 200V/s Op Amps Micropower Comparator with 1% Reference Micropower Quad Comparators with 1% Reference Low Quiescent Current High Efficiency Step-Down Converter 1.5A Max, Dual Precision Rail-to-Rail Input and Output Op Amp 300mA Low Dropout Regulator with Micropower Quiescent Current and Shutdown Micropower Precision Shunt Voltage Reference
C-Load is a trademark of Linear Technology Corporation.
12
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417 q (408) 432-1900 FAX: (408) 434-0507q TELEX: 499-3977 q www.linear-tech.com
U
2V TO 11V
+ -
2
7 8
LTC1540 1
CMOS ONE SHOT (CD4047)
Q Q
1540 F10
Figure 10. Nanopower Field Detector
COMMENTS 70V Max VOS, 5nA Max IBIAS C-LoadTM Op Amp Stable Driving Any Capacitive Load C-Load Op Amps Stable Driving Any Capacitive Load 1.182V 1% Reference, 10mV (Max) Input Offset LTC1443 Has 1.182V Reference, LTC1444/LTC1445 Have 1.221V Reference and Adjustable Hysteresis 10A Standby Current, 92% Efficiency, Space Saving 8-Pin MSOP Package 375V Max VOS, 250pA IBIAS, 25pA IOS 0.5V Dropout Voltage, 12A Quiescent Current, Adjustable Output 3V, 3.3V and 5V Fixed 1.25V, 2.5V, 4.096V, 5V Outputs, 10A Operating Current, 0.05% Initial Accuracy 25ppm/C Max Drift, SO-8, MSOP and TO-92 Packages
1540f LT/TP 0498 4K * PRINTED IN USA
(c) LINEAR TECHNOLOGY CORPORATION 1997

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