Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsPMICsPMIC - voltage reference Series Adjustable uMAX 8

19-2647; Rev 6; 8/12

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MAX6126

Ultra-High-Precision, Ultra-Low-Noise,

Series Voltage Reference

General Description

The MAX6126 is an ultra-low-noise, high-precision, low-

dropout voltage reference. This family of voltage refer-

ences feature curvature-correction circuitry and

high-stability, laser-trimmed, thin-film resistors that

result in 3ppm/°C (max) temperature coefficients and

an excellent ±0.02% (max) initial accuracy. The propri-

etary low-noise reference architecture produces a low

flicker noise of 1.3µV

P-P

and wideband noise as low as

60nV/√Hz (2.048V output) without the increased supply

current usually found in low-noise references. Improve

wideband noise to 35nV/√Hz and AC power-supply

rejection by adding a 0.1µF capacitor at the noise

reduction pin. The MAX6126 series mode reference

operates from a wide 2.7V to 12.6V supply voltage

range and load-regulation specifications are guaran-

teed to be less than 0.025Ω for sink and source cur-

rents up to 10mA. These devices are available over the

automotive temperature range of -40°C to +125°C.

The MAX6126 typically draws 380µA of supply current

and is available in 2.048V, 2.500V, 2.800V, 3.000V,

4.096V, and 5.000V output voltages. These devices

also feature dropout voltages as low as 200mV. Unlike

conventional shunt-mode (two-terminal) references that

waste supply current and require an external resistor,

the MAX6126 offers supply current that is virtually inde-

pendent of supply voltage and does not require an

external resistor. The MAX6126 is stable with 0.1µF to

10µF of load capacitance.

The MAX6126 is available in the tiny 8-pin µMAX

, as

well as 8-pin SO packages.

Applications

High-Resolution A/D and D/A Converters

ATE Equipment

High-Accuracy Reference Standard

Precision Current Sources

Digital Voltmeters

High-Accuracy Industrial and Process Control

Features

o Ultra-Low 1.3µV

P-P

Noise (0.1Hz to 10Hz, 2.048V

Output)

o Ultra-Low 3ppm/°C (max) Temperature Coefficient

o ±0.02% (max) Initial Accuracy

o Wide (V

OUT

+ 200mV) to 12.6V Supply Voltage

Range

o Low 200mV (max) Dropout Voltage

o 380µA Quiescent Supply Current

o 10mA Sink/Source-Current Capability

o Stable with C

LOAD

= 0.1µF to 10µF

o Low 20ppm/1000hr Long-Term Stability

o 0.025Ω (max) Load Regulation

o 20µV/V (max) Line Regulation

o Force and Sense Outputs for Remote Sensing

OUTS

I.C.*GNDS

I.C.*

OUTFIN

GND

SO/µMAX

TOP VIEW

MAX6126

*I.C. = INTERNALLY CONNECTED. DO NOT USE.

Pin Configuration

Ordering Information

PART TEMP RANGE

PIN-

PACKAGE

OUTPUT

VOLTAGE

(V)

MAXIMUM INITIAL

ACCURACY (%)

MAXIMUM TEMPCO

(-40°C to +85°C)

(ppm/°C)

MAX6126AASA21+ -40°C to +125°C 8 SO 2.048 0.02 3

MAX6126BASA21+ -40°C to +125°C 8 SO 2.048 0.06 5

MAX6126A21+ -40°C to +125°C 8 µMAX 2.048 0.06 3

Ordering Information continued at end of data sheet.

µMAX is a registered trademark of Maxim Integrated Products, Inc.

Denotes a lead(Pb)-free/RoHS-compliant package.

Summary of content (18 pages)

PAGE 1
MAX6126 Ultra-High-Precision, Ultra-Low-Noise, Series Voltage Reference General Description The MAX6126 is an ultra-low-noise, high-precision, lowdropout voltage reference. This family of voltage references feature curvature-correction circuitry and high-stability, laser-trimmed, thin-film resistors that result in 3ppm/°C (max) temperature coefficients and an excellent ±0.02% (max) initial accuracy. The proprietary low-noise reference architecture produces a low flicker noise of 1.
PAGE 2
MAX6126 Ultra-High-Precision, Ultra-Low-Noise, Series Voltage Reference ABSOLUTE MAXIMUM RATINGS (All voltages referenced to GND) GNDS ....................................................................-0.3V to +0.3V IN ........................................................................... -0.3V to +13V OUTF, OUTS, NR........ -0.3V to the lesser of (VIN + 0.3V) or +6V Output Short Circuit to GND or IN ..........................................
PAGE 3
MAX6126 Ultra-High-Precision, Ultra-Low-Noise, Series Voltage Reference ELECTRICAL CHARACTERISTICS—MAX6126_21 (VOUT = 2.048V) (continued) (VIN = 5V, CLOAD = 0.1µF, IOUT = 0, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS DYNAMIC CHARACTERISTICS Noise Voltage Turn-On Settling Time Capacitive-Load Stability Range eOUT tR CLOAD f = 0.1Hz to 10Hz 1.3 f = 1kHz, CNR = 0 60 f = 1kHz, CNR = 0.1µF 35 To VOUT = 0.
PAGE 4
MAX6126 Ultra-High-Precision, Ultra-Low-Noise, Series Voltage Reference ELECTRICAL CHARACTERISTICS—MAX6126_25 (VOUT = 2.500V) (continued) (VIN = 5V, CLOAD = 0.1µF, IOUT = 0, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER Dropout Voltage (Note 3) OUT Short-Circuit Current SYMBOL CONDITIONS VIN - VOUT ∆VOUT = 0.1% ISC Thermal Hysteresis (Note 2) ∆VOUT/ cycle Long-Term Stability ∆VOUT/ time TYP MAX IOUT = 5mA MIN 0.06 0.2 IOUT = 10mA 0.12 0.
PAGE 5
MAX6126 Ultra-High-Precision, Ultra-Low-Noise, Series Voltage Reference ELECTRICAL CHARACTERISTICS—MAX6126_28 (VOUT = 2.800V) (continued) (VIN = 5V, CLOAD = 0.1µF, IOUT = 0, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER OUT Short-Circuit Current Thermal Hysteresis (Note 2) Long-Term Stability SYMBOL ISC CONDTIONS MIN 160 Short to IN 20 ∆VOUT/cycle µMAX ∆VOUT/time TYP Short to GND MAX UNITS mA 80 ppm 100 ppm/ 1000hr f = 0.1Hz to 10Hz 1.
PAGE 6
MAX6126 Ultra-High-Precision, Ultra-Low-Noise, Series Voltage Reference ELECTRICAL CHARACTERISTICS—MAX6126_30 (VOUT = 3.000V) (continued) (VIN = 5V, CLOAD = 0.1µF, IOUT = 0, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER SYMBOL Line Regulation ∆VOUT/ ∆VIN Load Regulation ∆VOUT/ ∆IOUT Dropout Voltage (Note 3) OUT Short-Circuit Current CONDITIONS 3.2V ≤ VIN ≤ 12.
PAGE 7
MAX6126 Ultra-High-Precision, Ultra-Low-Noise, Series Voltage Reference ELECTRICAL CHARACTERISTICS—MAX6126_41 (VOUT = 4.096V) (continued) (VIN = 5V, CLOAD = 0.1µF, IOUT = 0, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER SYMBOL CONDITIONS TA = -40°C to +85°C Output Voltage Temperature Coefficient (Note 1) TCVOUT TA = -40°C to +125°C Line Regulation ∆VOUT/ ∆VIN Load Regulation ∆VOUT/ ∆IOUT Dropout Voltage (Note 3) OUT Short-Circuit Current 4.3V ≤ VIN ≤ 12.
PAGE 8
MAX6126 Ultra-High-Precision, Ultra-Low-Noise, Series Voltage Reference ELECTRICAL CHARACTERISTICS—MAX6126_50 (VOUT = 5.000V) (VIN = 5.5V, CLOAD = 0.1µF, IOUT = 0, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.
PAGE 9
MAX6126 Ultra-High-Precision, Ultra-Low-Noise, Series Voltage Reference ELECTRICAL CHARACTERISTICS—MAX6126_50 (VOUT = 5.000V) (continued) (VIN = 5.5V, CLOAD = 0.1µF, IOUT = 0, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) PARAMETER SYMBOL Turn-On Settling Time CONDITIONS To VOUT = 0.01% of final value tR MIN TYP CNR = 0 2 CNR = 0.1µF 20 MAX UNITS ms INPUT Supply Voltage Range VIN Quiescent Supply Current Guaranteed by line-regulation test 5.2 12.
PAGE 10
MAX6126 Ultra-High-Precision, Ultra-Low-Noise, Series Voltage Reference Typical Operating Characteristics (continued) (VIN = 5V for MAX6126_21/25/30/41, VIN = 5.5V for MAX6126_50, CLOAD = 0.1µF, IOUT = 0, TA = +25°C, unless otherwise specified.) (Note 5) MAX6126A_50 MAX6126_21 MAX6126_50 OUTPUT VOLTAGE TEMPERATURE DRIFT LOAD REGULATION LOAD REGULATION (VOUT = 5.000V) (µMAX) 5.000 4.999 2.0475 TA = -40°C 2.0470 MAX6126 toc06 TA = +25°C 2.0480 TA = +25°C 5.000 OUTPUT VOLTAGE (V) 5.001 5.
PAGE 11
MAX6126 Ultra-High-Precision, Ultra-Low-Noise, Series Voltage Reference Typical Operating Characteristics (continued) (VIN = 5V for MAX6126_21/25/30/41, VIN = 5.5V for MAX6126_50, CLOAD = 0.1µF, IOUT = 0, TA = +25°C, unless otherwise specified.) (Note 5) MAX6126_21 MAX6126_50 OUTPUT NOISE (0.1Hz TO 10Hz) OUTPUT NOISE (0.1Hz TO 10Hz) MAX6126 toc13 MAX6126 toc14 VOUT = 2.048V VOUT = 5V 0.
PAGE 12
MAX6126 Ultra-High-Precision, Ultra-Low-Noise, Series Voltage Reference Typical Operating Characteristics (continued) (VIN = 5V for MAX6126_21/25/30/41, VIN = 5.5V for MAX6126_50, CLOAD = 0.1µF, IOUT = 0, TA = +25°C, unless otherwise specified.) (Note 5) MAX6126_21 MAX6126_21 LOAD TRANSIENT LOAD TRANSIENT MAX6126 toc20 MAX6126 toc19 +1mA IOUT 500µA/div -1mA IOUT 5mA/div -100µA -10mA VOUT AC-COUPLED 10mV/div VOUT AC-COUPLED 50mV/div 400µs/div 1ms/div IOUT = -1mA TO -10mA VOUT = 2.
PAGE 13
MAX6126 Ultra-High-Precision, Ultra-Low-Noise, Series Voltage Reference Typical Operating Characteristics (continued) (VIN = 5V for MAX6126_21/25/30/41, VIN = 5.5V for MAX6126_50, CLOAD = 0.1µF, IOUT = 0, TA = +25°C, unless otherwise specified.) (Note 5) MAX6126 toc25 MAX6126 toc26 2.5006 5.5V 2.5004 VIN 2V/div VIN 2V/div 2.5002 GND GND VOUT (V) 5.5V TWO TYPICAL PARTS VOUT = 2.5V 2.5000 2.4998 VOUT 2V/div VOUT 1V/div MAX6126 toc27 MAX6126B_25 LONG-TERM STABILITY vs.
PAGE 14
MAX6126 Ultra-High-Precision, Ultra-Low-Noise, Series Voltage Reference Pin Description (VOUT + 200mV) TO 12.6V INPUT PIN 1 NAME NR 2 IN 3 GND FUNCTION Noise Reduction. Connect a 0.1µF capacitor to improve wideband noise. Leave unconnected if not used (see Figure 1). OUTF Positive Power-Supply Input Ground MAX6126 REFERENCE OUTPUT OUTS * 4 GNDS Ground-Sense Connection. Connect to ground connection at load. 5, 8 I.C. Internally Connected. Do not connect anything to these pins.
PAGE 15
MAX6126 Ultra-High-Precision, Ultra-Low-Noise, Series Voltage Reference racy is needed. The MAX6126 has the same type of Kelvin connection to cancel drops in the ground return line. Connect the load to ground and bring a connection from GNDS to exactly the same point. IN ISOURCE Applications Information Precision Current Source Figure 2 shows a typical circuit providing a precision current source. The OUTF output provides the bias current for the bipolar transistor.
PAGE 16
MAX6126 Ultra-High-Precision, Ultra-Low-Noise, Series Voltage Reference 10,000 1000 100 8 BIT TEMPERATURE COEFFICIENT (ppm/°C) 10 10 BIT 12 BIT 1 14 BIT 16 BIT 0.1 18 BIT 0.01 1 10 OPERATING TEMPERATURE RANGE (TMAX - TMIN) (°C) 20 BIT 100 Figure 4. Temperature Coefficient vs. Operating Temperature Range for a 1 LSB Maximum Error Typical Operating Circuit Chip Information PROCESS: BiCMOS (VOUT + 200mV) TO 12.6V INPUT IN OUTF MAX6126 REFERENCE OUTPUT OUTS * NR LOAD * GND GNDS *OPTIONAL.
PAGE 17
MAX6126 Ultra-High-Precision, Ultra-Low-Noise, Series Voltage Reference Ordering Information (continued) PART TEMP RANGE PINPACKAGE OUTPUT VOLTAGE (V) MAXIMUM INITIAL ACCURACY (%) MAXIMUM TEMPCO (-40°C to +85°C) (ppm/°C) MAX6126B21+ -40°C to +125°C 8 µMAX 2.048 0.1 7 MAX6126AASA25+ -40°C to +125°C 8 SO 2.500 0.02 3 MAX6126BASA25+ -40°C to +125°C 8 SO 2.500 0.06 5 MAX6126A25+ -40°C to +125°C 8 µMAX 2.500 0.06 3 MAX6126B25+ -40°C to +125°C 8 µMAX 2.500 0.
PAGE 18
MAX6126 Ultra-High-Precision, Ultra-Low-Noise, Series Voltage Reference Revision History REVISION NUMBER REVISION DATE 0 10/02 Initial release 1 3/03 Remove “future product” and “contact factory” notes 1, 16 2 6/03 Add “A” grade devices 1, 16 3 12/03 Change µMAX part number 1, 16 4 7/04 Add top mark to Ordering Information 1, 16 5 12/10 Add 2.