LM4140 High Precision Low Noise Low Dropout Voltage Reference
- SNVS053F June 2000 – September 2016 LM4140
  
  PRODUCTION DATA.

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DATA SHEET

LM4140 High Precision Low Noise Low Dropout Voltage Reference

1 Features

High Initial Accuracy: 0.1%
Ultra-Low Noise
Low Temperature Coefficient: 3 ppm/°C (A Grade)
Low Voltage Operation: 1.8V
Low Dropout Voltage: 20 mV (Typical) at 1mA
Supply Current: 230 µA (Typical), ≤ 1 µA Disable Mode
Enable Pin
Output Voltage Options: 1.024 V, 1.25 V, 2.048 V, 2.5 V, and 4.096 V
Custom Voltages From 0.5 V to 4.5 V
Temperature Range: 0°C to 70°C

2 Applications

Portable, Battery-Powered Equipment
Instrumentation and Test Equipment
Automotive
Industrial Process Control
Data Acquisition Systems
Medical Equipment
Precision Scales
Servo Systems
Battery Charging

3 Description

The LM4140 series of precision references are designed to combine high accuracy, low drift, and noise with low power dissipation in a small package.

The LM4140 is the industry's first reference with output voltage options lower than the bandgap voltage.

The key to the advance performance of the LM4140 is the use of EEPROM registers and CMOS DACs for temperature coefficient curvature correction and trimming of the output voltage accuracy of the device during the final production testing.

The major advantage of this method is the much higher resolution available with DACs than is available economically with most methods used by other bandgap references.

The low input and dropout voltage, low supply current, and output drive capability of the LM4140 makes this product an ideal choice for battery powered and portable applications.

The LM4140 is available in three grades (A, B, C) with 0.1% initial accuracy and 3, 6, and 10 ppm/°C temperature coefficients. For even lower temperature coefficients, contact Texas Instruments.

The device performance is specified over the temperature range 0°C to 70°C, and is available in compact 8-pin package.

For other output voltage options from 0.5 V to 4.5 V, contact Texas Instruments.

Device Information⁽¹⁾

PART NUMBER	PACKAGE	BODY SIZE (NOM)
LM4140	SOIC (8)	4.90 mm × 3.91 mm

For all available packages, see the orderable addendum at the end of the data sheet.

Typical Application

4 Revision History

Changes from E Revision (April 2013) to F Revision

Added ESD Ratings table, Feature Description section, Device Functional Modes, Application and Implementation section, Power Supply Recommendations section, Layout section, Device and Documentation Support section, and Mechanical, Packaging, and Orderable Information sectionGo
Added Thermal Information tableGo

Changes from D Revision (April 2005) to E Revision

Changed layout of National Semiconductor Data Sheet to TI formatGo

5 Pin Configuration and Functions

D Package

8-Pin SOIC

Top View

Pin Functions

PIN		TYPE⁽¹⁾	DESCRIPTION
NAME	NO.	TYPE⁽¹⁾	DESCRIPTION
Enable	3	I	Pulled to input for normal operation. Forcing this pin to ground turns off the output.
Ground	1, 4, 7, 8	G	Negative supply or ground connection. These pins must be connected to ground.
NC	5	—	This pin must be left open.
V_IN	2	I	Positive supply.
V_REF	6	O	Reference output. Capable of sourcing up to 8 mA.

(1) G = Ground, I = Input, O = Output

6 Specifications

6.1 Absolute Maximum Ratings

over operating free-air temperature range (unless otherwise noted)⁽¹⁾

	MIN	MAX	UNIT
Maximum voltage on any input pin	–0.3	5.6	V
Output short-circuit duration	Indefinite
Power dissipation (T_A = 25°C)⁽²⁾		345	mW
Storage temperature, T_stg	–65	150	°C

(1) Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under Recommended Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.

(2) Without PCB copper enhancements. The maximum power dissipation must be derated at elevated temperatures and is limited by T_JMAX (maximum junction temperature), R_θJA (junction to ambient thermal resistance) and T_A (ambient temperature). The maximum power dissipation at any temperature is: PDiss_MAX = (T_JMAX − T_A)/R_θJA up to the value listed in the Absolute Maximum Ratings. The R_θJA for the 8-pin SOIC package is 160°C/W.

6.2 ESD Ratings

			VALUE	UNIT
V_(ESD)	Electrostatic discharge	Human-body model (HBM), per ANSI/ESDA/JEDEC JS-001⁽¹⁾	±2000	V
V_(ESD)	Electrostatic discharge	Charged-device model (CDM), per JEDEC specification JESD22-C101⁽²⁾	±200	V

(1) JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.

(2) JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process.

6.3 Recommended Operating Conditions

over operating free-air temperature range (unless otherwise noted)

	MIN	NOM	MAX	UNIT
Ambient temperature	0		70	°C
Junction temperature	0		80	°C

6.4 Thermal Information

THERMAL METRIC⁽¹⁾		LM4140	UNIT
		D (SOIC)
		8 PINS
R_θJA	Junction-to-ambient thermal resistance	119.3	°C/W
R_θJC(top)	Junction-to-case (top) thermal resistance	52.3	°C/W
R_θJB	Junction-to-board thermal resistance	60.3	°C/W
ψ_JT	Junction-to-top characterization parameter	14.5	°C/W
ψ_JB	Junction-to-board characterization parameter	59.7	°C/W
R_θJC(bot)	Junction-to-case (bottom) thermal resistance	—	°C/W

(1) For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application report.

6.5 Electrical Characteristics

V_IN = 3 V for the 1.024-V and 1.25-V, V_IN = 5 V for all other voltage options, V_EN = V_IN, C_OUT = 1 µF⁽¹⁾, I_LOAD = 1 mA, and
T_A = T_J = 25°C (unless otherwise noted)

PARAMETER		TEST CONDITIONS			MIN⁽²⁾	TYP⁽³⁾	MAX⁽²⁾	UNIT
V_REF	Output voltage initial accuracy⁽⁴⁾	All versions					±0.1%
TCV_REF/°C	Temperature coefficient	0°C ≤ T_A ≤ 70°C		A grade			3	ppm/°C
				B grade			6
				C grade			10
ΔV_REF/ΔV_IN	Line regulation	1.024-V and 1.25-V options, 1.8 V ≤ V_IN ≤ 5.5 V		T_A = 25°C		50	300	ppm/V
		1.024-V and 1.25-V options, 1.8 V ≤ V_IN ≤ 5.5 V		0°C ≤ T_A ≤ 70°C			350
		All other voltage options, V_ref + 200 mV ≤ V_IN ≤ 5.5 V		T_A = 25°C		20	200
		All other voltage options, V_ref + 200 mV ≤ V_IN ≤ 5.5 V		0°C ≤ T_A ≤ 70°C			250
ΔV_REF/ΔI_LOAD	Load regulation	1 mA ≤ I_LOAD ≤ 8 mA	All other voltage options	T_A = 25°C		1	20	ppm/mA
			All other voltage options	0°C ≤ T_A ≤ 70°C			150
			4.096-V option	T_A = 25°C		5	35
			4.096-V option	0°C ≤ T_A ≤ 70°C			150
ΔV_REF	Long-term stability	1000 hours				60		ppm
ΔV_REF	Thermal hysteresis⁽⁵⁾	0°C ≤ T_A ≤ + 70°C				20		ppm
	Operating voltage	1.024-V and 1.25-V options, I_L = 1 mA to 8 mA, 0°C ≤ T_A ≤ 70°C			1.8		5.5	V
V_IN-V_REF	Dropout voltage⁽⁶⁾	2.048-V and 2.5-V options	I_L = 1 mA	T_A = 25°C		20	40	mV
			I_L = 1 mA	0°C ≤ T_A ≤ 70°C			45
			I_L = 8 mA	T_A = 25°C		160	235
			I_L = 8 mA	0°C ≤ T_A ≤ 70°C			400
		4.096-V option	I_L = 1 mA	T_A = 25°C		20	40
			I_L = 1 mA	0°C ≤ T_A ≤ 70°C			45
			I_L = 8 mA	T_A = 25°C		195	270
			I_L = 8 mA	0°C ≤ T_A ≤ 70°C			490
V_N	Output noise voltage⁽⁷⁾	0.1 Hz to 10 Hz				2.2		µV_PP
I_S(ON)	Supply current	I_LOAD = 0 mA	All other voltage options	T_A = 25°C		230	320	µA
			All other voltage options	0°C ≤ T_A ≤ 70°C			375
			4.096-V option	T_A = 25°C		265	350
			4.096-V option	0°C ≤ T_A ≤ 70°C			400
I_S(OFF)	Supply current	V_Enable < 0.4 V		T_A = 25°C		0.01		µA
I_S(OFF)	Supply current	V_Enable < 0.4 V		0°C ≤ T_A ≤ 70°C			1	µA
V_H	Logic high input voltage	0°C ≤ T_A ≤ 70°C			0.8 × V_IN			V
I_H	Logic high input current					2		nA
V_L	Logic low input voltage	0°C ≤ T_A ≤ 70°C					0.4	V
I_L	Logic low input current					1		nA
I_SC	Short-circuit current	T_A = 25°C			8.5	20	35	mA
I_SC	Short-circuit current	0°C ≤ T_A ≤ 70°C					40	mA

(1) For proper operation, a 1-µF capacitor is required between the output pin and the GND pin of the device.

(2) Limits are 100% production tested at 25°C. Limits over the operating temperature range are ensured through correlation using Statistical Quality Control (SQC) methods. The limits are used to calculate TI's Average Outgoing Quality Level (AOQL).

(3) Typical numbers are at 25°C and represent the most likely parametric norm.

(4) High temperature and mechanical stress associated with PCB assembly can have significant impact on the initial accuracy of the LM4140 and may create significant shifts in V_REF.

(5) Thermal hysteresis is defined as the changes in 25°C output voltage before and after the cycling of the device from 0°C to 70°C.

(6) Dropout voltage is defined as the minimum input to output differential voltage at which the output voltage drops by 0.5% below the value measured with V_IN = 3 V for the 1.024-V and 1.25-V, V_IN = 5 V for all other voltage options.

(7) The output noise is based on 1.024 V option. Output noise is linearly proportional to V_REF.

6.6 Typical Characteristics

T_A = 25°C, no load, C_OUT = 1 µF, V_IN = 3 V for 1.024-V and 1.25-V, and 5 V for all other voltage options, and V_IN = V_EN (unless otherwise noted). The 1-µF output capacitor is actively discharged to ground (see ON/OFF Operation for more details).

Figure 1. Power Up and Down Ground Current

Figure 3. Line Transient Response

Figure 5. Output Impedance

1.024-V and 1.25-V options require 1.8-V supply

Figure 7. Dropout Voltage vs Load Current

Figure 9. Total Current (I_S(OFF)) vs Supply Voltage

Figure 11. Spectral Noise Density (0.1 Hz to 10 Hz)

Figure 13. Ground Current vs Load Current

Figure 15. Load Regulation vs Temperature

Figure 17. Line Regulation vs Temperature

Figure 19. Short-Circuit Current vs Temperature

Figure 21. Typical Temperature Coefficient (Sample of 5 Parts)

Figure 2. Enable Response

Figure 4. Load Transient Response

Figure 6. Power Supply Rejection Ratio

Figure 8. Output Voltage Change vs Sink Current (I_SINK)

Figure 10. Total Current (I_S(ON)) vs Supply Voltage

Figure 12. Spectral Noise Density (10 Hz to 100 kHz)

Figure 14. Long-Term Drift

Figure 16. Output Voltage vs Load Current

Figure 18. I_Q vs Temperature

Figure 20. Dropout Voltage vs Load Current (V_OUT) = 2 V

7 Detailed Description

7.1 Overview

The LM4140 device is a high-precision series voltage reference available in 5 difference output voltage options, including the 1.024-V option below the bandgap voltage. The series reference can operate with input voltage as low as VREF + 400 mV over temperature, consuming 400 µA or less over temperature depending on voltage option. While in shutdown, the device consumes 10 nA (typical).

7.2 Functional Block Diagram

7.3 Feature Description

7.3.1 ON/OFF Operation

The LM4140 is designed to quickly reduce both V_REF and I_Q to zero when turned off. V_REF is restored in less than 200 µs when turned on. During the turnoff, the charge across the output capacitor is discharged to ground through internal circuitry.

The LM4140 is turned off by pulling the enable input low, and turned on by driving the input high. If this feature is not to be used, the enable pin must be tied to the V_IN to keep the reference on at all times (the enable pin must not be left floating).

To ensure proper operation, the signal source used to drive the enable pin must be able to swing above and below the specified high and low voltage thresholds which ensure an ON or OFF state (see Electrical Characteristics).

The ON/OFF signal may come from either a totem-pole output, or an open-collector output with pullup resistor to the LM4140 input voltage. This high-level voltage may exceed the LM4140 input voltage, but must remain within the absolute maximum rating for the enable pin.

7.4 Device Functional Modes

Table 1 lists the operational modes of the LM4140.

Table 1. Operational Modes

ENABLE PIN	LOGIC STATE	DESCRIPTION
EN = V_IN	1	Normal operation, device powered up
EN = Ground	0	Device in shutdown