Datasheet

ManualsBrandsLinear Technology ManualsIntegrated Circuits (ICs)Voltage Reference 2.5 V SOT-23 SOT-23

LT6656

6656fa

Output Voltage Temperature Drift

LT6656-2.5

TEMPERATURE (°C)

–40

2.498

2.499

OUT

(V)

2.500

2.501

2.502

2.503

–20 0 20 40

6652 TA01b

60 80

38 TYPICAL UNITS

Basic Connection

Typical applicaTion

DescripTion

1µA Precision Series

Voltage Reference

The LT

6656 is a small precision voltage reference that

draws less than 1µA of supply current and can operate

with a supply voltage within 10mV of the output voltage.

The LT6656 offers an initial accuracy of 0.05% and tem-

perature drift of 10ppm/°C. The combined low power and

precision characteristics are ideal for portable and battery

powered instrumentation.

The LT6656 can supply up to 5mA of output drive with

65ppm/mA of load regulation, allowing it to be used as

the supply voltage and the reference input to a low power

ADC. The LT6656 can accept a supply voltage up to 18V

and withstand the reversal of the input connections.

The LT6656 output is stable with 1µF or larger output

capacitance and operates with a wide range of output

capacitor ESR.

This reference is fully speciﬁed for operation from –40°C

to 85°C, and is functional over the extreme temperature

range of –55°C to 125°C. Low hysteresis and a consistent

temperature drift are obtained through advanced design,

processing and packaging techniques.

The LT6656 is offered in the 6-lead SOT-23 package.

L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. ThinSOT is

a trademark of Linear Technology Corporation. All other trademarks are the property of their

respective owners.

FeaTures

applicaTions

Low Drift

A Grade: 10 ppm/°C Max

B Grade: 20 ppm/°C Max

High Accuracy

A Grade: 0.05% Max

B Grade: 0.1% Max

Ultralow Supply Current: 850nA

High Output Drive Current: 5mA Min

Low Dropout Voltage: 10mV Max

Fully Speciﬁed from –40°C to 85°C

Operational from –55°C to 125°C

Wide Supply Range to 18V

Reverse Input/Output Protection

Available Output Voltage Options:

1.25V, 2.048V, 2.5V, 3V, 3.3V, 4.096V and 5V

Thermal Hysteresis: 25ppm

Low Proﬁle (1mm) ThinSOT™ Package

Precision A/D and D/A Converters

Portable Gas Monitors

Battery- or Solar-Powered Systems

Precision Regulators

Low Voltage Signal Processing

Micropower Remote Sensing

2.51V ≤ V

≤ 18V

0.1µF 1µF

OUT

2.5V

6656 TA01a

LT6656-2.5

OUT

GND

Summary of content (18 pages)

PAGE 1
LT6656 1µA Precision Series Voltage Reference Features n n n n n n n n n n n n Description Low Drift A Grade: 10 ppm/°C Max B Grade: 20 ppm/°C Max High Accuracy A Grade: 0.05% Max B Grade: 0.1% Max Ultralow Supply Current: 850nA High Output Drive Current: 5mA Min Low Dropout Voltage: 10mV Max Fully Specified from –40°C to 85°C Operational from –55°C to 125°C Wide Supply Range to 18V Reverse Input/Output Protection Available Output Voltage Options: 1.25V, 2.048V, 2.5V, 3V, 3.3V, 4.
PAGE 2
LT6656 Absolute Maximum Ratings Pin Configuration (Note 1) Input Voltage............................................................±20V Output Voltage............................................ –0.3V to 20V Output Voltage Above Input Voltage..........................20V Specified Temperature Range Commercial.............................................. 0°C to 70°C Industrial..............................................–40°C to 85°C Operating Temperature Range................
PAGE 3
LT6656 Order Information LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION SPECIFIED TEMPERATURE RANGE LT6656ACS6-4.096#PBF LT6656ACS6-4.096#TRPBF LTFNV 6-Lead Plastic TSOT-23 0°C to 70°C LT6656BCS6-4.096#PBF LT6656BCS6-4.096#TRPBF LTFNV 6-Lead Plastic TSOT-23 0°C to 70°C LT6656AIS6-4.096#PBF LT6656AIS6-4.096#TRPBF LTFNV 6-Lead Plastic TSOT-23 –40°C to 85°C LT6656BIS6-4.096#PBF LT6656BIS6-4.
PAGE 4
LT6656 Electrical Characteristics The l denotes the specifications which apply over the specified temperature range, otherwise specifications are at TA = 25°C. VIN = VOUT + 0.5V (for LT6656-1.25, VIN = 2.2V), CL = 1μF, IL = 0,unless otherwise noted. PARAMETER CONDITIONS MIN Output Voltage Error LT6656A LT6656B –0.05 –0.10 Output Voltage Temperature Coefficient (Note 4) LT6656A LT6656B l l Line Regulation VIN = (VOUT + 0.5V) to 18V LT6656-2.048, LT6656-2.5, LT6656-3, LT6656-3.3, LT6656-4.
PAGE 5
LT6656 Electrical Characteristics Note 1: Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. Exposure to any Absolute Maximum Rating condition for extended periods may affect device reliability and lifetime. Note 2: If the parts are stored outside of the specified temperature range, the output may shift due to hysteresis. Note 3: The stated temperature is typical for soldering of the leads during manual rework.
PAGE 6
LT6656 Typical Performance Characteristics Minimum Supply Voltage vs Load Current Supply Current vs Input Voltage VON 1 2.5V OPTION SHOWN VON MOVES WITH VOLTAGE OPTION 0.1 0 2 4 1.25V OPTION INITIAL VIN = 2.2V 1.8 ∆VOUT = 0.1% 1.6 1.4 1.2 TA = 125°C TA = 85°C TA = 25°C TA = –40°C TA = –55°C 1.0 0.8 0.
PAGE 7
LT6656 Typical Performance Characteristics Output Impedance vs Frequency 100 10 1.25V OPTION 2.5V OPTION 5V OPTION 100 1k FREQUENCY (Hz) 1k 100 10 1 10k IL = 0, CL = 1µF IL = 0, CL = 10µF IL = 100µA, CL = 1µF IL = 100µA, CL = 10µF 10 100 1k FREQUENCY (Hz) 6656 G21 TA = 125°C TA = 85°C TA = 25°C TA = –55°C 0 ALL OPTIONS VIN = GND TA = 125°C TA = 85°C TA = 25°C TA = –55°C 0 5 10 15 OUTPUT VOLTAGE (V) 15 10 2.
PAGE 8
LT6656 Typical Performance Characteristics 250 VIN = VOUT + 0.5V CL = 1µF 400 INTEGRATED NOISE (µVRMS) INTEGRATED NOISE (µVRMS) 500 Integrated 10Hz to 1kHz Noise vs Load Current 300 5V OPTION 200 2.5V OPTION 100 ALL OPTIONS 150 CL = 1µF IL = 0 2.5V OPTION 200 150 100 CL = 0.47µF CL = 1µF CL = 10µF CL = 47µF 50 1.25V OPTION 0 0.1µ 1µ 10µ 100µ LOAD CURRENT (A) 1m 10m Long-Term Drift 200 0 0.
PAGE 9
LT6656 Applications Information Long Battery Life Output Voltage Options Series references have a large advantage over shunt style references. Shunt references require a resistor from the power supply to operate. This resistor must be chosen to supply the maximum current that can be demanded by the load. When the load is not operating at this maximum current, the shunt reference must always sink this current, resulting in high dissipation and shortened battery life.
PAGE 10
LT6656 Applications Information 0µA IOUT 100µA 2.52V VOUT 2.50V 2.48V 5ms/DIV 6656 F03 Figure 3. Transient Response, 0µA to 100µA Load Step (R2 = 24.9k, R1 = Open) 1mA IOUT 2mA In application circuits where the LT6656 is experiencing a load step greater than 5µA, such as an ADC reference and supply implementation, the settling time will typically remain less than 8ms, regardless of the output settling from a previous load step. The settling time can be estimated by the following equation: 2.52V VOUT 2.
PAGE 11
LT6656 Applications Information VIN input pulled to ground, the reverse output protection of the LT6656 limits the output current to typically less than 30µA. The current versus reverse voltage is shown in the Typical Performance Characteristics section. 3.25V 2.75V IL = 0 Long-Term Drift VOUT 10mV/DIV The photo in Figure 7 shows the output response to a 0.5V input step in both a no-load and 5µA load condition.
PAGE 12
LT6656 Applications Information 30 NUMBER OF UNITS 2.5V OPTION VIN = 3V 25 CL = 1µF IL = 0 0°C TO 25°C 70°C TO 25°C 300 380s TP = 260°C TL = 217°C TS(MAX) = 200°C 225 20 TS = 190°C 15 RAMP DOWN tP 30s T = 150°C 150 tL 130s RAMP TO 150°C 10 75 40s 5 120s 0 –60 –40 –20 0 20 HYSTERESIS (ppm) 40 0 60 0 2 6656 F08 Figure 8. 0°C to 70°C Hysteresis 20 18 12 10 8 6 4 10 6656 F10 2.5V OPTION VIN = 3V 6 C = 1µF L IL = 0 5 3 CYCLES 1 CYCLE 4 3 2 1 2 0 7 2.
PAGE 13
LT6656 Typical Applications Regulator Reference Low Power ADC Reference The robust input and output of the LT6656 along with its high output current make it an excellent precision low power regulator as well as a reference. The LT6656 would be a good match with a small, low power microcontroller. Using the LT6656 as a regulator reduces power consumption, decreases solution size and increases the accuracy of the microcontroller’s on board ADC.
PAGE 14
LT6656 Typical Applications Extended Supply Range Reference VCC UP TO 160V 330k MMBT5551 BZX584C12 0.1µF 2.2µF IN VOUT OUT LT6656-2.5 1µF 6656 TA03 Boosted Output Current Reference 3.6V ≤ VCC ≤ 18V 2207 + 10µF 2N2905 0.1µF IN VOUT 40mA MAX OUT LT6656-2.5 1µF 6656 TA04 Micropower Regulator, IQ = 2µA, Sink Up to 8mA 3V ≤ VCC ≤ 18V IN LT6656-2.5 + OUT 0.1µF 1µF 2.5V LT6003 – 6656 TA06 ADC Reference and Bridge Excitation Supply 3.8V ≤ VIN ≤ 18V IN 0.1µF LT6656-3.3 3.3V ≤ VCC ≤ 5.
PAGE 15
LT6656 Typical Applications Low Power Precision High Voltage Supply Monitor, IQ = 1.4µA, High Voltage Supply Load = 10µA 100V 105V OVERVOLTAGE THRESHOLD VCC 9.53M 3 + 4 – 6.5V ≤ VCC ≤ 10V IN LT6656-5 OUT 0.1µF 1µF 475k 7 OVERVOLTAGE FLAG LTC1540 5 6 1, 2 6656 TA08 2-Terminal Current Source + + IN LT6656-1.25 GND 0.1µF OUT VREF LT6003 R1 – 1µF R3 R2 – IOUT 6656 TA09 VREF ¥ R2 ´ 1 R1 §¦ R3 ¶µ Precision Current and Boosted Reference, IQ = 5.
PAGE 16
LT6656 Package Description S6 Package 6-Lead Plastic TSOT-23 (Reference LTC DWG # 05-08-1636) 0.62 MAX 2.90 BSC (NOTE 4) 0.95 REF 1.22 REF 3.85 MAX 2.62 REF 1.4 MIN 2.80 BSC 1.50 – 1.75 (NOTE 4) PIN ONE ID RECOMMENDED SOLDER PAD LAYOUT PER IPC CALCULATOR 0.30 – 0.45 6 PLCS (NOTE 3) 0.95 BSC 0.80 – 0.90 0.20 BSC 0.01 – 0.10 1.00 MAX DATUM ‘A’ 0.30 – 0.50 REF 0.09 – 0.20 (NOTE 3) NOTE: 1. DIMENSIONS ARE IN MILLIMETERS 2. DRAWING NOT TO SCALE 3. DIMENSIONS ARE INCLUSIVE OF PLATING 4.
PAGE 17
LT6656 Revision History REV DATE DESCRIPTION PAGE NUMBER A 7/10 Voltage options added (1.25, 2.048, 3, 3.3), reflected throughout the data sheet 1 to 18 6656fa 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.
PAGE 18
LT6656 Typical Application Reference Regulator for Micropower DAC, Total IQ = 4.8µA 5.1V ≤ VIN ≤ 18V IN LT6656-5 OUT 0.1µF 5V 10µF VREF VCC CS SCK SDI DAC A 0V TO 5V OUTPUT DAC B 0V TO 5V OUTPUT LTC1662 GND 6656 TA07 Related Parts PART NUMBER DESCRIPTION COMMENTS LT1389 Nanopower Precision Shunt Voltage Reference 0.05% Max 10ppm/°C Max, 800nA Supply LTC1440 Micropower Comparator with Reference 3.7µA Max Supply Current, 1% 1.