LMx85-1.2, LM385B-1.2 Micropower Voltage References
- SLVS075J April 1989 – January 2015 LM285-1.2 , LM385-1.2 , LM385B-1.2
  
  PRODUCTION DATA.

Full reading width

DATA SHEET

LMx85-1.2, LM385B-1.2 Micropower Voltage References

1 Features

Operating Current Range
- LM285-1.2: 10 μA to 20 mA
- LM385-1.2: 15 μA to 20 mA
- LM385B-1.2: 15 μA to 20 mA
1% and 2% Initial Voltage Tolerance
Reference Impedance
- LM385-1.2: 1 Ω MAX at 25°C
- All devices: 1.5 Ω MAX over Full
  Temperature Range
Very Low Power Consumption
Interchangeable with Industry Standard
LM285-1.2 and LM385-1.2

2 Applications

Portable Meter References
Portable Test Instruments
Battery-Operated Systems
Current-Loop Instrumentation
Panel Meters

3 Description

These micropower, two-terminal, band-gap voltage references operate over a 10-μA to 20-mA current range and feature exceptionally low dynamic impedance and good temperature stability. On-chip trimming provides tight voltage tolerance. The band-gap reference for these devices has low noise and long-term stability.

The design makes these devices exceptionally tolerant of capacitive loading and, thus, easier to use in most reference applications. The wide dynamic operating temperature range accommodates varying current supplies, with excellent regulation.

The extremely low power drain of this series makes them useful for micropower circuitry. These voltage references can be used to make portable meters, regulators, or general-purpose analog circuitry, with battery life approaching shelf life. The wide operating current range allows them to replace older references with tighter-tolerance parts.

Device Information⁽¹⁾

PART NUMBER	PACKAGE (PIN)	BODY SIZE (NOM)
LMx85-1.2	SOIC (8)	4.90 mm × 3.91 mm
	SOP (8)	6.20 mm × 5.30 mm
	TSSOP (8)	3.00 mm × 4.40 mm
	TO-226 (3)	4.30 mm × 4.30 mm

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

4 Simplified Schematic

5 Revision History

Changes from I Revision (December 2005) to J Revision

Added Applications, Device Information table, Pin Functions table, ESD Ratings table, Thermal Information table, Typical Characteristics, 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 section.Go
Deleted Ordering Information table.Go

6 Pin Configuration and Functions

Pin Functions

PIN			TYPE	DESCRIPTION
NAME	LP	D, PS or PW	TYPE	DESCRIPTION
ANODE	1	4	I	Shunt Current/Voltage input
CATHODE	2	8	O	Common pin, normally connected to ground
NC	3	1, 2, 3, 5, 6, 7	—	No internal connection

7 Specifications

7.1 Absolute Maximum Ratings

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

		MIN	MAX	UNIT
I_R	Reverse Current		30	mA
I_F	Forward Current		10	mA
T_J	Operating virtual junction temperature		150	°C
T_stg	Storage temeprature	–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.

7.2 ESD Ratings

			VALUE	UNIT
V_(ESD)	Electrostatic discharge	Human body model (HBM), per ANSI/ESDA/JEDEC JS-001, all pins⁽¹⁾	±2000	V
V_(ESD)	Electrostatic discharge	Charged device model (CDM), per JEDEC specification JESD22-C101, all pins⁽²⁾	±1000	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.

7.3 Recommended Operating Conditions

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

			MIN	MAX	UNIT
I_ZZ	Reference current		0.01	20	mA
T_A	Operating free-air temperature	LM285-1.2	–40	85	°C
T_A	Operating free-air temperature	LM385-1.2, LM385B-1.2	0	70	°C

7.4 Thermal Information

THERMAL METRIC⁽¹⁾		LMx85-1.2				UNIT
		D	LP	PS	PW
		8 PINS	3 PINS	8 PINS	8 PINS
R_θJA	Junction-to-ambient thermal resistance	97	140	95	149	°C/W

(1) For more information about traditional and new thermal metrics, see the IC Package Thermal Metrics application report, SPRA953.

7.5 Electrical Characteristics

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

PARAMETER		TEST CONDITIONS	T_A⁽¹⁾	LM285-1.2			LM385-1.2			LM385B-1.2			UNIT
PARAMETER		TEST CONDITIONS	T_A⁽¹⁾	MIN	TYP	MAX	MIN	TYP	MAX	MIN	TYP	MAX	UNIT
V_Z	Reference voltage	I_Z = I(min) to 20 mA⁽²⁾	25°C	1.223	1.235	1.247	1.21	1.235	1.26	1.223	1.235	1.247	V
α_VZ	Average temperature coefficient of reference voltage⁽³⁾	I_Z = I(min) to 20 mA⁽²⁾	Full Range		±20			±20			±20		ppm/°C
Δ_VZ	Change in reference voltage with current	I_Z = I(min) to 1 mA⁽²⁾	25°C			1			1			1	mV
		I_Z = I(min) to 1 mA⁽²⁾	Full Range			1.5			1.5			1.5
		I_Z = I(min) to 20 mA	25°C			12			20			20
		I_Z = I(min) to 20 mA	Full Range			30			30			30
ΔV_Z/Δt	Long-term change in reference voltage	I_Z = 100 µA	25°C		±20			±20			±20		ppm/khr
I_Z(min)	Minimum reference current		Full Range		8	10		8	15		8	15	µA
Z_Z	Reference impedance	I_Z = 100 µA, f = 25 Hz	25°C		0.2	0.6		0.4	1		0.4	1	Ω
Z_Z	Reference impedance	I_Z = 100 µA, f = 25 Hz	Full Range			1.5			1.5			1.5	Ω
V_n	Broadband noise voltage	I_Z = 100 µA, f = 10 Hz to 10 kHz	25°C		60			60			60		µV

(1) Full range is −40°C to 85°C for the LM285-1.2 and 0°C to 70°C for the LM385-1.2 and LM385B-1.2.

(2) I(min) = 10 μA for the LM285-1.2 and 15 μA for the LM385-1.2 and LM385B-1.2

(3) The average temperature coefficient of reference voltage is defined as the total change in reference voltage divided by the specified temperature range.

7.6 Typical Characteristics

Figure 1. Reverse Current vs Reverse Voltage

Figure 2. Reference Voltage Change vs Reverse Current

Figure 3. Forward Voltage vs Forward Current

Figure 5. Reference Impedance vs Reference Current

Figure 7. Output Noise Voltage vs Cutoff Frequency

Figure 4. Reference Voltage vs Free-Air Temperature

Figure 6. Noise Voltage vs Frequency