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LTC6652

6652fe

For more information www.linear.com/6652

Features

applications

Description

Precision Low Drift Low

Noise Buffered Reference

The LTC

6652 family of precision, low drift, low noise

references is fully speciﬁed over the temperature range

of –40°C to 125°C. High order curvature compensation

allows these references to achieve a low drift of less than

5ppm/°C with a predictable temperature characteristic and

an output voltage accuracy of ±0.05%. The performance

over temperature should appeal to automotive, high perfor-

mance industrial and other high temperature applications.

The LTC6652 voltage references can be powered from

supply voltages up to 13.2V. They boast low noise, ex-

cellent load regulation, source and sink capability and

exceptional line rejection, making them a superior choice

for demanding precision applications. A shutdown mode

allows power consumption to be reduced when the refer-

ence is not needed. The optional output capacitor can be

left off when space constraints are critical.

The LTC6652 references are offered in an 8-lead MSOP

package and an 8-lead LS8 package. The LS8 is a 5mm

× 5mm surface mount hermetic package that provides

outstanding stability.

L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear

Technology Corporation. All other trademarks are the property of their respective owners.

Output Voltage Temperature Drift

Low Drift:

A-Grade 5ppm/°C Max

B-Grade 10ppm/°C Max (MSOP8)

B-Grade 8ppm/°C Max (LS8)

High Accuracy:

A Grade ±0.05% Max

B-Grade ±0.1% Max

Low Noise: 2.1ppm

P-P

(0.1Hz to 10Hz)

100% Tested at –40°C, 25°C and 125°C

Sinks and Sources Current: ±5mA

Low Power Shutdown: <2µA Maximum

Thermal Hysteresis (LS8): 45ppm (–40°C to 125°C)

Long-Term Drift (LS8): 20ppm/√kHr

Low Dropout: 300mV

Available Output Voltage Options: 1.25V, 2.048V, 2.5V,

3V, 3.3V, 4.096V, 5V

8-Lead MSOP and 5mm × 5mm Surface Mount

Hermetic Packages

Automotive Control and Monitoring

High Temperature Industrial

High Resolution Data Acquisition Systems

Instrumentation and Process Control

Precision Regulators

Medical Equipment

Basic Connection

typical application

TEMPERATURE (°C)

–40

–0.050

OUT

ACCURACY (%)

–0.025

0.025

0.050

–20 0 20 40

6652 TA01b

60 80 100 125

2.8V ≤ V

≤ 13.2V

0.1µF

(OPTIONAL)

OUT

1µF

(OPTIONAL)

OUT

2.5V

6652 TA01a

LTC6652-2.5

OUT

GND

SHDN

Summary of content (20 pages)

PAGE 1
LTC6652 Precision Low Drift Low Noise Buffered Reference Features n n n n n n n n n n n Description Low Drift: A-Grade 5ppm/°C Max B-Grade 10ppm/°C Max (MSOP8) B-Grade 8ppm/°C Max (LS8) High Accuracy: A Grade ±0.05% Max B-Grade ±0.1% Max Low Noise: 2.1ppmP-P (0.
PAGE 2
LTC6652 Absolute Maximum Ratings (Note 1) Input Voltage VIN to GND........................................... –0.3V to 13.2V SHDN to GND.............................–0.3V to (VIN + 0.3V) Output Voltage VOUT............................................–0.3V to (VIN + 0.3V) Output Short-Circuit Duration....................... Indefinite Operating Temperature Range................. –40°C to 125°C Storage Temperature Range (Note 2)...... –65°C to 150°C Lead Temperature Range (Soldering, 10 sec) (Note 9).......
PAGE 3
LTC6652 order information LEAD FREE FINISH PART MARKING* PACKAGE DESCRIPTION SPECIFIED TEMPERATURE RANGE LTC6652AHLS8-2.5#PBF † 665225 8-Lead Ceramic LCC 5mm × 5mm –40°C to 125°C LTC6652BHLS8-2.5#PBF † 665225 8-Lead Ceramic LCC 5mm × 5mm –40°C to 125°C Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container. Consult LTC Marketing for information on non-standard lead based finish parts.
PAGE 4
LTC6652 Electrical Characteristics The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C, VIN = VOUT + 0.5V, unless otherwise noted. PARAMETER CONDITIONS Minimum Operating Voltage (Note 5) ISOURCE = 5mA, VOUT Error ≤ 0.1% LTC6652-1.25, LTC6652-2.048 LTC6652-2.5, LTC6652-3, LTC6652-3.3, LTC6652-4.
PAGE 5
LTC6652 Typical Performance Characteristics Characteristic curves are similar for most LTC6652s. Curves from the LTC6652-1.25, LTC6652-2.5 and the LTC6652-5 represent the extremes and typical of the voltage options. Characteristic curves for other output voltages fall between these curves and can be estimated based on their output. 1.25V Output Voltage Temperature Drift 1.2510 1.25V Line Regulation 1.25V Load Regulation (Sourcing) 1.2506 3 TYPICAL PARTS 0 1.2500 1.2495 125°C 1.2502 1.2500 25°C 1.
PAGE 6
LTC6652 Typical Performance Characteristics Characteristic curves are similar for most LTC6652s. Curves from the LTC6652-1.25, LTC6652-2.5 and the LTC6652-5 represent the extremes and typical of the voltage options. Characteristic curves for other output voltages fall between these curves and can be estimated based on their output. 2.5V Output Voltage Temperature Drift 2.5V Load Regulation (Sourcing) 0 2.5010 3 TYPICAL PARTS OUTPUT VOLTAGE CHANGE (ppm) –20 2.5005 2.
PAGE 7
LTC6652 Typical Performance Characteristics Characteristic curves are similar for most LTC6652s. Curves from the LTC6652-1.25, LTC6652-2.5 and the LTC6652-5 represent the extremes and typical of the voltage options. Characteristic curves for other output voltages fall between these curves and can be estimated based on their output. 2.5V Low Frequency 0.1Hz to 10Hz Transient Noise 2.5V Output Voltage Noise Spectrum 600 NOISE VOLTAGE (nV/√Hz) OUTPUT NOISE (1µV/DIV) 500 400 300 200 100 0 0.
PAGE 8
LTC6652 Typical Performance Characteristics Characteristic curves are similar for most LTC6652s. Curves from the LTC6652-1.25, LTC6652-2.5 and the LTC6652-5 represent the extremes and typical of the voltage options. Characteristic curves for other output voltages fall between these curves and can be estimated based on their output. 5V Output Voltage Temperature Drift 5.002 3 TYPICAL PARTS 5.000 4.998 800 5.001 SUPPLY CURRENT (µA) 5.003 1000 900 OUTPUT VOLTAGE (V) REFERENCE VOLTAGE (V) 5.
PAGE 9
LTC6652 Typical Performance Characteristics Characteristic curves are similar for most LTC6652s. Curves from the LTC6652-1.25, LTC6652-2.5 and the LTC6652-5 represent the extremes and typical of the voltage options. Characteristic curves for other output voltages fall between these curves and can be estimated based on their output. Power Supply Rejection Ratio vs Frequency 100 –30 COUT = 1µF –40 –50 –60 COUT = 10µF –70 –80 VTH(UP) 2.0 10 VTRIP (V) –20 2.
PAGE 10
LTC6652 Block Diagram 2 3 VIN + SHDN VOUT BANDGAP 6 – 4 GND 6652 BD Applications Information Bypass and Load Capacitors The LTC6652 voltage references do not require an input capacitor, but a 0.1µF capacitor located close to the part improves power supply rejection. The LTC6652 voltage references are stable with or without a capacitive load. For applications where an output capacitor is beneficial, a value of 0.1µF to 10µF is recommended depending on load conditions.
PAGE 11
LTC6652 Applications Information VIN 3.5V IOUT 3V VOUT 500mV/DIV 5mA 0mA VOUT 200mV/DIV COUT = 0µF 500µs/DIV COUT = 0µF 6652 F02 Figure 2. Transient Response Without Output Capacitor VIN 250µs/DIV 6652 F05 Figure 5. LTC6652-2.5 Sinking Current Without Output Capacitor 0mA IOUT –5mA 3.5V 3V VOUT 500mV/DIV VOUT 200mV/DIV COUT = 1µF 500µs/DIV 6652 F03 COUT = 1µF 6652 F06 Figure 6. LTC6652-2.5 Sourcing Current with Output Capacitor Figure 3.
PAGE 12
LTC6652 Applications Information 2.8V ≤ VIN ≤ 13.2V VIN 2V/DIV C1 1µF R1 20k VIN LTC6652-2.5 SHDN TO µC VOUT 1V/DIV COUT = 0µF 100µs/DIV VOUT VOUT GND 2N7002 6652 F10 C2 1µF Figure 10. Open-Drain Shutdown Circuit 6652 F08 Figure 8. Start-Up Response without Output Capacitor SHDN 1V/DIV VIN 2V/DIV VOUT 1V/DIV VOUT 1V/DIV ILOAD = 5mA COUT = 1µF 100µs/DIV 6652 F09 1ms/DIV 6652 F11 Figure 11. Shutdown Response with 5mA Load Figure 9.
PAGE 13
LTC6652 Applications Information 80 80 40 40 LTC6652-2.5 LS8 PACKAGE 4 TYPICAL PARTS 60 TA = 30°C ppm ppm LTC6652-2.5 MS8 PACKAGE 3 TYPICAL PARTS 60 TA = 35°C 20 20 0 0 –20 –20 –40 0 300 900 600 HOURS 1200 –40 1500 6652 F12a Figure 12a. MS8 Long-Term Drift 35 9 8 30 600 400 HOURS 800 1000 6652 F12b 25°C TO 125°C TO 25°C 25°C TO –40°C TO 25°C 7 25 NUMBER OF UNITS NUMBER OF UNITS 200 Figure 12b.
PAGE 14
LTC6652 Applications Information PC Board Layout The mechanical stress of soldering a surface mount voltage reference to a PC board can cause the output voltage to shift and temperature coefficient to change. These two changes are not correlated. For example, the voltage may shift, but the temperature coefficient may not. To reduce the effects of stress-related shifts, mount the reference near the short edge of the PC board or in a corner.
PAGE 15
LTC6652 Applications Information 10 7 NUMBER OF UNITS NUMBER OF UNITS 8 6 4 2 0 1X 3X 6 5 4 3 2 1 0 0.06 –0.1 –0.06 –0.02 0 0.02 0.1 OUTPUT VOLTAGE SHIFT DUE TO IR REFLOW (%) 0.002 0.010 0.018 –0.014 –0.006 OUTPUT VOLTAGE SHIFT DUE TO IR REFLOW (%) 6652 F15b 6652 F15a Figure 15b. LS8 Output Voltage Shift Due to IR Reflow 0.7 0.06 0.6 0.05 0.5 TA = 25°C 0.04 POWER (W) DISSIPATION (W) Figure 15a. MS8 Output Voltage Shift Due to IR Reflow 0.4 0.3 5mA LOAD 0.03 0.02 0.2 0.1 0.
PAGE 16
LTC6652 Typical Applications Extended Supply Range Reference Extended Supply Range Reference 4V TO 30V R1 330k R1 VIN BZX84C18 LTC6652-2.5 VOUT SHDN C1 0.1µF 6V TO 160V R2 4.7k ON SEMI MMBT5551 VOUT VIN GND C2 OPTIONAL 6652 TA02 GND 6652 TA03 VCC ≥ 1.75V V+ ≥ (VOUT + 1.8V) C1 1µF 2, 3 R1 220Ω VIN LTC6652-2.5 2N2905 SHDN LTC6652-2.5 VOUT 500Ω VEE ≤ –3V C2 OPTIONAL Boosted Output Current Negative Rail Circuit 4, 5, 7, 8 VOUT LTC6652-2.5 VOUT BZX84C18 C1 0.1µF C1 0.
PAGE 17
LTC6652 Package Description Please refer to http://www.linear.com/designtools/packaging/ for the most recent package drawings. MS8 Package 8-Lead Plastic MSOP (Reference LTC DWG # 05-08-1660 Rev F) 3.00 ± 0.102 (.118 ± .004) (NOTE 3) 0.889 ± 0.127 (.035 ± .005) 5.23 (.206) MIN 0.254 (.010) 7 6 5 0.52 (.0205) REF 3.00 ± 0.102 (.118 ± .004) (NOTE 4) 4.90 ± 0.152 (.193 ± .006) DETAIL “A” 0° – 6° TYP GAUGE PLANE 3.20 – 3.45 (.126 – .136) 0.53 ± 0.152 (.021 ± .006) DETAIL “A” 0.42 ± 0.038 (.
PAGE 18
LTC6652 Package Description Please refer to http://www.linear.com/designtools/packaging/ for the most recent package drawings. LS8Package Package LS8 8-Leadless 8-Pin LeadlessChip ChipCarrier Carrier(5mm (5mm× ×5mm) 5mm) (ReferenceLTC LTCDWG DWG##05-08-1852 05-08-1852 Rev Ø) (Reference 8 2.50 ±0.15 PACKAGE OUTLINE 7 1 6 2 2.54 ±0.15 5 3 1.50 ±0.15 4 0.70 ±0.05 5.00 SQ ±0.15 5.80 SQ ±0.15 APPLY SOLDER MASK TO AREAS THAT ARE NOT SOLDERED 5.00 SQ ±0.15 1.45 ±0.10 0.95 ±0.10 4.20 SQ ±0.
PAGE 19
LTC6652 Revision History (Revision history begins at Rev C) REV DATE DESCRIPTION C 11/09 Change to Typical Performance Characteristics. PAGE NUMBER D 8/12 Change to Typical Application. Addition of 5mm × 5mm Hermetic LS8 Package. Update to Electrical Characteristics to Include LS8 Package. Addition of Long Term Drift, Hysteresis, IR Drift Plots for LS8 Package. E 1/13 6 14 1, 2, 3, 12, 18 4 13, 15 Addition of Humidity Sensitivity Information.
PAGE 20
LTC6652 Typical Application Improved Reference Supply Rejection in a Data Converter Application LTC1657 DATA VCC 16 D/A GND VDAC REF VIN R1 50k VOUT LTC6652 REF SHDN C1 0.1µF C2 10µF GND COUT 1µF V1 V2 V3 V4 LTC1605 A/D 16 DOUT GND 6652 TA05 Related Parts PART NUMBER DESCRIPTION COMMENTS LT1460 Micropower Series References 0.075% Max, 10ppm/°C Max, 20mA Output Current LT1461 Micropower Series Low Dropout 0.