LM385

LIN D O C # : 385 LM385/385B 1.2 & 2.5V M I C R O P O W E R V O LTA G E R E F E R E N C E T HE I NFINITE P OWER OF I N N O VAT I O N P RODUCTION D ATA S HEET DESCRIPTION The LM385/385B Micropower Voltage References are two terminal bandgap reference diodes designed and optimized for accurate low power operation in portable and other power sensitive systems. Operating currents are guaranteed from as low as 15µA up to 20mA for the LM385/385B-1.2, and 20µA up to 20mA for the LM385/385B-2.5, giving designers a great deal of flexibility in optimizing power consumption, noise and ultimate application performance. As an added feature, the references output impedance is extraordinarily low over the entire operating range of quiescent currents. This enables an extremely wide dynamic load range with little effect on the overall reference accuracy. The LM385 family is available in fixed 1.2V and 2.5V reference values. Process and circuit design optimization provide for high accuracy with initial tolerance values of 1% for the LM385B-1.2, 2% for the LM385-1.2, 1.5% for the LM385B-2.5, and 3% for the LM385-2.5. Complementing their initial accuracy, the bandgap reference is temperature compensated to deliver 20ppm performance over the 0° to 70°C operating temperature range. The LM385 family from Linfinity is a pin-for-pin replacement for the LM385/ 385B family of voltage references. K E Y F E AT U R E S s GUARANTEED 1% INITIAL ACCURACY (LM385B-1.2) s GUARANTEED 2.5% INITIAL ACCURACY (LM385-1.2) s GUARANTEED 1.5% INITIAL ACCURACY (LM385B-2.5) s GUARANTEED 3% INITIAL ACCURACY (LM385-2.5) p GUARANTEED 20µA OPERATING CURRENT p LOW TEMPERATURE COEFFICIENT p OPERATING CURRENT OF 20µA TO 20mA p VERY LOW DYNAMIC IMPEDANCE . . . 1Ω A P P L I C AT I O N S s p p p PORTABLE METER REFERENCES PORTABLE TEST INSTRUMENTS BATTERY OPERATED SYSTEMS CURRENT LOOP INSTRUMENTATION PRODUCT HIGHLIGHT 1.2V R E F E R E N C E 5V MICROPOWER REFERENCE FROM 9V BATTERY 9V 38k 1.2V LM385-1.2V 200k 2.5V LM385-2.5V PA C K A G E O R D E R I N F O R M AT I O N TA (°C) Reference Voltage 1.2V Initial Tolerance ±30mV ±12mV ±75mV ±38mV DM Plastic SOIC 8-pin LM385DM-1.2 LM385BDM-1.2 LM385DM-2.5 LM385BDM-2.5 LP Plastic TO-92 3-pin LM385LP-1.2 LM385BLP-1.2 LM385LP-2.5 LM385BLP-2.5 0 to 70 2.5V Note: All surface-mount packages are available in Tape & Reel. Append the letter "T" to part number. (i.e. LM385DM-2.5T) F O R F U R T H E R I N F O R M AT I O N C A L L ( 7 1 4 ) 8 9 8 - 8 1 2 1 Copyright © 1996 Rev. 1.2 7/96 11861 W ESTERN A VENUE, G ARDEN G ROVE , CA. 92841 1 PRODUCT DATABOOK 1996/1997 LM385/385B 1 .2 & 2.5V M I C R O P O W E R V O LTA G E R E F E R E N C E P RODUCTION D ATA S HEET A B S O L U T E M A X I M U M R AT I N G S (Note 1) PACKAGE PIN OUTS Reverse Breakdown Current .................................................................................... 30mA Forward Current ........................................................................................................ 10mA Operating Temperature Range LM385 ........................................................................................................... 0°C to 70°C Storage Temperature Range ...................................................................... -65°C to 150°C Lead Temperature (soldering, 10 seconds) ............................................................. 300°C Note 1. Values beyond which damage may occur. All voltages are specified with respect to ground, and all currents are positive into the specified terminal N/C N/C N/C ANODE 1. 2. 3. 4. CATHODE N/C 6. CATHODE 5. N/C 8. 7. DM PACKAGE (Top View) T H E R MAL DATA DM PACKAGE: THERMAL RESISTANCE-JUNCTION TO AMBIENT, θ JA LP PACKAGE: THERMAL RESISTANCE-JUNCTION TO AMBIENT, θ JA 165ºC/W 165ºC/W 1. ANODE 2. CATHODE 3. N/C LP PACKAGE (Top View) The θ JA numbers are guidelines for the thermal performance of the device/pc-board system. All of the above assume no ambient airflow. 2 Copyright © 1996 Rev. 1.2 7/96 PRODUCT DATABOOK 1996/1997 LM385/385B 1 .2 & 2.5V M I C R O P O W E R V O LTA G E R E F E R E N C E P RODUCTION D ATA S HEET ELECTRICAL CHARACTERISTICS (Unless otherwise specified, these specifications apply to TA = 25ºC. Typ number represents TA = 25ºC value.) LM385/385B-1.2 Parameter Reverse Breakdown Voltage Average Temperature Coefficient Minimum Operating Current Reverse Breakdown Voltage Chang with Current Reverse Dynamic Impedance Wide Band Noise (RMS) Long Term Stability LM385 LM385B Symbol VZ ∆VZ ∆Temp IMIN e ∆I R rz en ∆VZ ∆Time IMIN ≤ IR ≤ IMAX IMIN ≤ IR ≤ IMAX IR = 100µA Test Conditions LM385/385B-1.2 Min. Typ. Max. 1.205 1.223 1.235 1.235 20 8 1.260 1.247 Units V V ppm/°C µA mV mV Ω µV ppm/kHr ∆VZ IMIN ≤ IR ≤ 1mA 1mA ≤ IR ≤ 20mA IR = 100µA IR = 100µA, 10Hz ≤ f ≤ 10kHz IR = 100µA, TA = 25°C ± 0.1°C 15 1.5 20 1 60 20 LM385/385B-2.5 Parameter Reverse Breakdown Voltage Average Temperature Coefficient Minimum Operating Current Reverse Breakdown Voltage Chang with Current Reverse Dynamic Impedance Wide Band Noise (RMS) Long Term Stability LM385 LM385B Symbol VZ ∆VZ ∆Temp IMIN e ∆I R rz en ∆VZ ∆Time IMIN ≤ IR ≤ IMAX IMIN ≤ IR ≤ IMAX IR = 100µA Test Conditions LM385/385B-2.5 Min. Typ. Max. 2.425 2.462 2.500 2.500 20 13 2.575 2.538 Units V V ppm/°C µA mV mV Ω µV ppm/kHr ∆VZ IMIN ≤ IR ≤ 1mA 1mA ≤ IR ≤ 20mA IR = 100µA, f = 20Hz IR = 100µA, 10Hz ≤ f ≤ 10kHz IR = 100µA, TA = 25°C ± 0.1°C 20 2 20 1 120 20 GRAPH / CURVE INDEX Characteristic Curves LM385/385B-1.2 FIGURE # 1. 2. 3. 4. 5. 6. 7. RESPONSE TIME REVERSE CHARACTERISTICS FORWARD CHARACTERISTICS TEMPERATURE DRIFT REVERSE VOLTAGE CHANGE REVERSE DYNAMIC IMPEDANCE NOISE VOLTAGE FIGURE # 8. 9. Characteristic Curves LM385/385B-2.5 RESPONSE TIME REVERSE CHARACTERISTICS 10. FORWARD CHARACTERISTICS 11. TEMPERATURE DRIFT 12. REVERSE DYNAMIC IMPEDANCE 13. NOISE VOLTAGE Copyright © 1996 Rev. 1.2 7/96 3 PRODUCT DATABOOK 1996/1997 LM385/385B 1 .2 & 2.5V M I C R O P O W E R V O LTA G E R E F E R E N C E P RODUCTION D ATA S HEET C H A R A C T E R I S T I C C U R V E S — LM385/385B-1.2V FIGURE 1. — RESPONSE TIME FIGURE 2. — REVERSE CHARACTERISTICS 100 Output Voltage 1.5V TA = 0 to 70°C Reverse Current - (µA) 1.0V 0.5V 0 VIN 36k VOUT 10 Input Voltage 1 5V 0 0.1 0 50 100 500 550 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 Time - (µs) Reverse Voltage - (V) FIGURE 3. — FORWARD CHARACTERISTICS 1.2 FIGURE 4. — TEMPERATURE DRIFT 1.242 TA = 25°C IR = 100µA 1.24 0.8 Reference Voltage - (V) 0.1 1 10 100 Forward Voltage - (V) 1.238 1.236 1.234 1.232 1.23 1.228 0.4 0 0.01 1.226 0 10 20 30 40 50 60 70 Forward Current - (mA) Temperature - (°C) 4 Copyright © 1996 Rev. 1.2 7/96 PRODUCT DATABOOK 1996/1997 LM385/385B 1 .2 & 2.5V M I C R O P O W E R V O LTA G E R E F E R E N C E P RODUCTION D ATA S HEET C H A R A C T E R I S T I C C U R V E S — LM385/385B-1.2V FIGURE 5. — REVERSE VOLTAGE CHANGE 16 14 FIGURE 6. — REVERSE DYNAMIC IMPEDANCE 1000 Output Voltage Change - (mV) Dynamic Impedance - (Ω) 12 10 8 6 4 2 0 -2 -4 0.01 TA = 0 to 70°C 100 TA = 25°C IR = 100µA 10 1 0.1 0.1 1 10 100 10 100 1k 10k 100k Reverse Current - (mA) (f) Frequency - (Hz) FIGURE 7. — NOISE VOLTAGE 800 700 (VN) Noise Voltage - (nV/ Hz) 600 500 400 300 200 100 IR = 100µA TA = 25°C 100 1k 10k 100k 10 (f) Frequency - (Hz) Copyright © 1996 Rev. 1.2 7/96 5 PRODUCT DATABOOK 1996/1997 LM385/385B 1 .2 & 2.5V M I C R O P O W E R V O LTA G E R E F E R E N C E P RODUCTION D ATA S HEET C H A R A C T E R I S T I C C U R V E S — LM385/385B-2.5V FIGURE 8. — RESPONSE TIME FIGURE 9. — REVERSE CHARACTERISTICS Output Voltage 4.0V 100 TA = 25°C 2.0V TA = 25°C VIN 0 24K Reverse Current - (µA) VOUT 10 Input Voltage 1 5 0 0.1 0 1.0 2.0 3.0 4.0 5.0 Time - (100µs/Div.) Reverse Voltage - (V) FIGURE 10. — FORWARD CHARACTERISTICS 1.0 FIGURE 11. — TEMPERATURE DRIFT 2.52 TA = 25°C 0.8 2.515 Reference Voltage - (V) Forward Voltage - (V) 2.51 2.505 2.5 2.495 2.49 2.485 0.6 0.4 0.2 0 0.001 0.01 0.1 1 10 100 2.48 -40 20 0 20 40 60 80 100 Forward Current - (mA) Temperature - (°C) 6 Copyright © 1996 Rev. 1.2 7/96 PRODUCT DATABOOK 1996/1997 LM385/385B 1 .2 & 2.5V M I C R O P O W E R V O LTA G E R E F E R E N C E P RODUCTION D ATA S HEET C H A R A C T E R I S T I C C U R V E S — LM385/385B-2.5V FIGURE 12. — REVERSE DYNAMIC IMPEDANCE 100 FIGURE 13. — NOISE VOLTAGE TA = 25°C IR = 100µA (VN) Noise Voltage - (nV/ Hz) 1800 1500 Dynamic Impedance - (Ω) 10 1200 900 600 1 300 0.1 10 IR = 100µA TA = 25°C 100 1k 10k 100k 100 1k 10k 100k 10 (f) Frequency - (Hz) (f) Frequency - (Hz) Copyright © 1996 Rev. 1.2 7/96 7