NSC LM369DRC, LM369DN, LM369DMX, LM369DM Datasheet

December 1994

LM169/LM369 Precision Voltage Reference

General Description

The LM169/LM369 are precision monolithic temperaturecompensated voltage references. They are based on a buried zener reference as pioneered in the LM199 references, but do not require any heater, as they rely on special tem- perature-compensation techniques (Patent Pending). The LM169 makes use of thin-film technology enhanced by the discrete laser trimming of resistors to achieve excellent Temperature coefficient (Tempco) of Vout (as low as 1 ppm/§C), along with tight initial tolerances (as low as 0.05% max). The trim scheme is such that individual resistors are cut open rather than being trimmed (partially cut), to avoid resistor drift caused by electromigration in the trimmed area. The LM169 also provides excellent stability vs. changes in input voltage and output current (both sourcing and sinking). The devices have a 10.000V output and will operate in either series or shunt mode; the output is short-circuit-proof to ground. A trim pin is available which permits fine-trimming of Vout, and also permits filtering to greatly decrease the output noise by adding a small capacitor (0.05 to 0.5 mF).

Features

Y Low Tempco	3 ppm/§C (max)
Y Excellent initial accuracy	g5 mV (max)
Y Excellent line regulation	4 ppm/V (max)
Y Excellent output impedance	g0.8X (max)
Y Excellent thermal regulation	g20 ppm/100 mW (max)

YLow noise

YEasy to filter output noise

YOperates in series or shunt mode

Applications

YHigh-Resolution Data Acquisition Systems

YDigital volt meters

YWeighing systems

YPrecision current sources

YTest Equipment

Connection Diagrams

Metal Can Package (H)

TL/H/9110 ± 1

Top View

(Case is connected to ground.)

*Do not connect; internal connection for factory trims.

Order Number LM169H, LM169BH,

LM169H/883, LM369H or LM369BH

See NS Package Number H08C

Dual-In-Line Package (N)

or S.O. Package (M)

TL/H/9110 ± 5

Top View

Order Number LM369DM, LM369DMX,** LM369N, LM369BN, LM369CN or LM369DN

See NS Package Number M08A or N08E

**X denotes 2500 units on Tape and Reel and is not included in the device part number marking

TO-226 Plastic Package (RC)

TL/H/9110 ± 28

Bottom View

Order Number LM369DRC

See NS Package Number RC03A

TeflonÉ and MylarÉ are registered trademarks of E.I. DuPont Corp.

Reference Voltage Precision LM169/LM369

C1995 National Semiconductor Corporation

TL/H/9110

RRD-B30M115/Printed in U. S. A.

Absolute Maximum Ratings (Note 8)

If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/Distributors for availability and specifications.

Input Voltage (Series Mode)	35V
Reverse Current (Shunt Mode)	50 mA
Power Dissipation (Note 7)	600 mW
Storage Temperature Range	b60§C to a150§C
Operating Temperature Range	(Tj min to Tj max)
LM169H, LM169H/883	b55§C to a125§C
LM369	0§C to a70§C

Soldering Information	a260§C
DIP (N) or Plastic (RC) Package, 10 sec.
H08 (H) Package, 10 sec.	a300§C
SO (M) Package, Vapor Phase (60 sec.)	a215§C
Infrared (15 sec.)	a220§C

See AN-450 ``Surface Mounting Methods and Their Effect on Product Reliability'' (Appendix D) for other methods of soldering surface mount devices.

ESD Tolerance
Czap e 100 pF, Rzap e 1.5k	800V

Electrical Characteristics, LM169, LM369 (Note 1)

				Tested	Design	Units
						(Max
	Parameter	Conditions	Typical	Limits	Limit
						Unless
				(Notes 2, 13)	(Note 3)
						Noted)
	Vout Nominal		a10.000			V
	Vout Error	(Note 11)	50	g500		ppm
			0.50	g5		mV
	Vout Tempco					ppm/§C
	LM169B, LM369B	Tmin k Tj k Tmax	1.0	3.0	Ð
	LM169, LM369	Tmin k Tj k Tmax	2.7	5.0	Ð	ppm/§C
	LM369C	Tmin k Tj k Tmax	6	10	Ð	ppm/§C
	(Note 6) (Note 11)
	Line Regulation	13V s VIN s 30V	2.0	4.0	8.0	ppm/V
	Load Regulation
	Sourcing	0 to 10 mA	a3	g8.0	20.0	ppm/mA
	Sinking (Note 12)	0 to b10 mA	a80	a150		ppm/mA
	(Note 4, Note 9)
	Thermal Regulation	(t e 10 msec
	Sourcing	After Load	3.0	g20	Ð	ppm/100 mW
	Sinking (Note 12)	is Applied)	3.0	Ð	Ð	ppm/100 mW
	(Note 5)
	Supply Current		1.4	1.8	2.0	mA
	DSupply Current	13V s VIN s 30V	0.06	0.12	0.2	mA
	Short Circuit		27	15	11	mA min
	Current			50	65	mA max
	Noise Voltage	10 Hz to 1 kHz	10	30	Ð	mV rms
		0.1 Hz to 10 Hz	4	Ð	Ð	mV p-p
		(10 Hz to 10 kHz,	4	Ð	Ð	mV rms
		Cfilter e 0.1 mF)
	Long-term	1000 hours,	6	Ð	Ð	ppm
	Stability	Tj k Tmax
	(Non-Cumulative)	(Measured at
	(Note 10)	a25§C)
	Temperature	DT e 25§C	3	Ð	Ð	ppm
	Hysteresis of Vout
	Output Shift		1500	2600	Ð	ppm
	per 1 mA at Pin 5

2

Electrical Characteristics LM369D (Note 1)

				Tested	Design	Units
						(Max
	Parameter	Conditions	Typical	Limits	Limit
						Unless
				(Notes 2, 13)	(Note 3)
						Noted)
	Vout Nominal		a10.000			V
	Vout Error,		70	g1000	Ð	ppm
	LM369D		0.7	g10.0	Ð	mV
	Vout Tempco	Tmin s Tj s Tmax	5		30	ppm/§C
	(Note 6)
	Line Regulation	13V s VIN s 30V	2.4	g6.0	12	ppm/V
	Load Regulation
	Sourcing	0 to 10 mA	a3	g12	g25	ppm/mA
	Sinking (Note 12)	0 to b10 mA	a80	a160		ppm/mA
	(Note 4, Note 9)
	Thermal Regulation	(t e 10 msec
	Sourcing	After Load	4.0	g25	Ð	ppm/100 mW
	Sinking (Note 12)	is Applied)	4.0	Ð	Ð	ppm/100 mW
	(Note 5)
	Supply Current		1.5	2.0	2.4	mA
	DSupply Current	13V s VIN s 30V	0.06	0.16	0.3	mA
	Short Circuit		27	14	10	mA min
	Current			50	65	mA max
	Noise Voltage	10 Hz to 1 kHz	10	30	Ð	mV rms
		0.1 Hz to 10 Hz	4	Ð	Ð	mV p-p
		(10 Hz to 10 kHz,	4	Ð	Ð	mV rms
		Cfilter e 0.1 mF)
	Long-Term	1000 Hours,	8	Ð	Ð	ppm
	Stability	Tj k Tmax
	(Non-Cumulative)	(Measured at
		a25§C)
	Temperature	DT e 25§C	5	Ð	Ð	ppm
	Hysteresis of Vout
	Output Shift		1500	2800	Ð	ppm
	Per 1 mA at Pin 5

Note 1: Unless otherwise noted, these conditions apply: Tj e a25§C, 13V s Vin s 17V, 0 s Iload s 1.0 mA, CL e s 200 pF. Specifications in BOLDFACED TYPE apply over the rated operating temperature range.

Note 2: Tested limits are guaranteed and 100% tested in production.

Note 3: Design Limits are guaranteed (but not 100% production tested) over the indicated temperature and supply voltage ranges. These limits are not to be used to calculate outgoing quality levels.

Note 4: The LM169 has a Class B output, and will exhibit transients at the crossover point. This point occurs when the device is required to sink approximately 1.0 mA. In some applications it may be advantageous to pre-load the output to either Vin or to ground, to avoid this crossover point.

Note 5: Thermal regulation is defined as the change in the output voltage at a time T after a step change of power dissipation of 100 mW.

Note 6: Temperature Coefficient of VOUT is defined as the worst-case DVout measured at Specified Temperatures divided by the total span of the Specified Temperature Range (see graphs). There is no guarantee that the Specified Temperatures are exactly at the minimum or maximum deviation.

Note 7: In metal can (H), iJ-C is 75§C/W and iJ-A is 150§C/W. In plastic DIP, iJ-A is 160§C/W. In S0-8, iJ-A is 180§C/W, in TO-226, iJ-A is 160§C/W.

Note 8: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. DC and AC electrical specifications are not guaranteed beyond the Rated Operating Conditions.

Note 9: Regulation is measured at constant temperature using pulse testing with a low duty cycle. Changes in output voltage due to heating effects are covered under the specifications for Thermal Regulation and Tempco. Load Regulation is measured at a point on the output pin 1/8× below the bottom of the package.

Note 10: Consult factory for availability of devices with Guaranteed Long-term Stability.

Note 11: Consult factory for availability of devices with tighter Accuracy and Tempco Specifications.

Note 12: In Sinking mode, connect 0.1 mF tantalum capacitor from output to ground.

Note 13: A military RETS electrical test specification is available on request.

3

Typical Performance Characteristics (Note 1)

	Dropout Voltage vs
Quiescent Current vs Input	Output Current (Series	Output Change vs
Voltage and Temperature	Mode Sourcing Current)	Output Current

		TL/H/9110 ± 6
		LM169 Temperature
	Output Noise vs Filter	Coefficient Specified
Output Noise vs Frequency	Capacitor	Temperatures (see Note 6)

TL/H/9110 ± 24	TL/H/9110 ± 25
	LM369 Temperature	TL/H/9110 ± 26
	Coefficient Specified	Typical Temperature Coefficient Calculations:
	Temperatures (see Note 6)	LM169 (see curve above):
		T.C. e 1.6 mV/(180§ c 10V)
		e 8.9 c 10b7 e 0.89 ppm/§C
		LM369 (see curve at left):
		T.C. e 0.5 mV/(75§ c 10V)
		e 6.7 c 10b7 e 0.67 ppm/§C

TL/H/9110 ± 27

4

Application Hints

The LM169/LM369 can be applied in the same way as any other voltage reference. The adjacent Typical Applications Circuits suggest various uses for the LM169/LM369. The LM169 is recommended for applications where the highest stability and lowest noise is required over the full military temperature range. The LM369 is suitable for limited-tem- perature operation. The curves showing the Noise vs. Capacitance in the Typical Performance Characteristics section show graphically that a modest capacitance of 0.1 to 0.3 microfarads can cut the broadband noise down to a level of only a few microvolts, less than 1 ppm of the output voltage. The capacitor used should be a low-leakage type. For the temperature range 0 to 50§C, polyester or MylarÉ will be suitable, but at higher temperatures, a premium film capacitor such as polypropylene is recommended. For operation at a125§C, a TeflonÉ capacitor would be required, to ensure sufficiently low leakage. Ceramic capacitors may seem to do the job, but are not recommended for production use, as the high-K ceramics cannot be guaranteed for low leakage, and may exhibit piezo-electric effects, converting vibration or mechanical stress into excessive electrical noise.

Additionally, the inherent superiority of the LM169/369's buried Zener diode provides freedom from low-frequency noise, wobble, and jitter, in the frequency range 0.01 to 10 Hertz, where capacitive filtering is not feasible.

Pins 1, 3, 7, and 8 of the LM169/369 are connected to internal trim circuits which are used to trim the device's output voltage and Tempco during final testing at the factory. Do not connect anything to these pins, or improper operation may result. These pins would not be damaged by a short to ground, or by Electrostatic Discharges; however, keep them away from large transients or AC signals, as stray capacitance could couple noises into the output. These pins may be cut off if desired. Alternatively, a shield foil can be laid out on the printed circuit board, surrounding these pins and pin 5, and this guard foil can be connected to ground or to Vout, effectively acting as a guard against AC coupling and DC leakages.

The trim pin (pin 5) should also be guarded away from noise signals and leakages, as it has a sensitivity of 15 millivolts of DVout per microampere. The trim pin can also be used in

the circuits shown, to provide an output trim range of g10 millivolts. Trimming to a wider range is possible, but is not recommended as it may degrade the Tempco and the Tempco linearity at temperature extremes. For example, if the output were trimmed up to 10.240V, the Tempco would be degraded by 8 ppm/§C. As a general rule, Tempco will be degraded by 1 ppm/§C per 30 mV of output adjustment.

The output can sink current as well as source it, but the output impedance is much better for sourcing current. Also, the LM169/369 requires a 0.1 mF tantalum capacitor (or, 0.1 mF in series with 10X) bypass from the output to ground, for stable operation in shunt mode (output sinking current). The output has a class-B stage, so if the load current changes from sourcing to sinking, an output transient will occur. To avoid this transient, it may be advisable to preload the output with a few milliamperes of load to ground. The LM169/369 does have an excellent tolerance of load capacitance, and in cases of load transients, electrolytic or tantalum capacitors in the range 1 to 500 microfarads have been shown to improve the output impedance without degrading the dynamic stability of the device. The LM169/369 are rated to drive an output of g10 mA, but for best accuracy, any load current larger than 1 mA can cause thermal errors (such as, 1 mA c 5V c 4 ppm/100 mW e 0.2 ppm or 2 microvolts) and degrade the ultimate precision of the output voltage.

The output is short-circuit-proof to ground. However, avoid overloads at high ambient temperatures, as a prolonged short-circuit may cause the junction temperature to exceed the Absolute Maximum Temperature. The device does not include a thermal shut-down circuit. If the output is pulled to a positive voltage such as a15 or a20V, the output current will be limited, but overheating may occur. Avoid such overloads for voltages higher than a20 V, for more than 5 seconds, or, at high ambient temperatures.

The LM169/369 has an excellent long-term stability, and is suitable for use in high-resolution Digital Voltmeters or Data Acquisition systems. Its long-term stability is typically 3 to 10 ppm per 1000 hours when held near Tmax, and slightly better when operated at room temperature. Contact the factory for availability of devices with proven long-term stability.

Typical Applications

		Series Reference with
		Optional Filter
Series Reference	Shunt Reference with Optional Trim	for Reduced Noise

TL/H/9110 ± 2

TL/H/9110 ± 4

TL/H/9110 ± 3

NOTE: Pin numbers for H, M or N packages.

5