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 H E I N F I N I T E P O W E R O F I N N O VA T I O N P D R O D U C T I O N 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 15A up to 20mA for the LM385/385B-1.2, and 20A 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 A T A S H E E T K E Y F E AT U R E S GUARANTEED 1% INITIAL ACCURACY (LM385B-1.2) GUARANTEED 2.5% INITIAL ACCURACY (LM385-1.2) GUARANTEED 1.5% INITIAL ACCURACY (LM385B-2.5) GUARANTEED 3% INITIAL ACCURACY (LM385-2.5) p GUARANTEED 20A OPERATING CURRENT p LOW TEMPERATURE COEFFICIENT p OPERATING CURRENT OF 20A TO 20mA p VERY LOW DYNAMIC IMPEDANCE . . . 1 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 70C operating temperature range. The LM385 family from Linfinity is a pin-for-pin replacement for the LM385/ 385B family of voltage references. A P P L I C AT I O N 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 MICROPOWER REFERENCE FROM 9V BATTERY 5V 9V 200k 38k 2.5V 1.2V LM385-2.5V LM385-1.2V PA C K A G E O R D E R I N F O R M AT I O N Reference Voltage TA (C) 1.2V 0 to 70 2.5V Initial Tolerance SOIC DM Plastic 8-pin TO-92 LP Plastic 3-pin 30mV LM385DM-1.2 LM385LP-1.2 12mV 75mV 38mV LM385BDM-1.2 LM385DM-2.5 LM385BDM-2.5 LM385BLP-1.2 LM385LP-2.5 LM385BLP-2.5 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 (c) 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 R O D U C T I O N A B S O L U T E M A X I M U M R AT I N G S D A T A S H E E T PACKAGE PIN OUTS (Note 1) Reverse Breakdown Current .................................................................................... 30mA Forward Current ........................................................................................................ 10mA Operating Temperature Range LM385 ........................................................................................................... 0C to 70C Storage Temperature Range ...................................................................... -65C to 150C Lead Temperature (soldering, 10 seconds) ............................................................. 300C 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 8. 2. 7. 3. 4. DM PACKAGE (Top View) 2. CATHODE 3. N/C DM PACKAGE: 165C/W LP PACKAGE: THERMAL RESISTANCE-JUNCTION TO AMBIENT, JA CATHODE N/C 6. CATHODE 5. N/C 1. 1. ANODE T H E R MAL DATA THERMAL RESISTANCE-JUNCTION TO AMBIENT, JA N/C N/C N/C ANODE 165C/W LP PACKAGE (Top View) The JA numbers are guidelines for the thermal performance of the device/pc-board system. All of the above assume no ambient airflow. 2 Copyright (c) 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 R O D U C T I O N D A T A S H E E T ELECTRICAL CHARACTERISTICS (Unless otherwise specified, these specifications apply to TA = 25C. Typ number represents TA = 25C value.) LM385/385B-1.2 Parameter Reverse Breakdown Voltage Symbol LM385 LM385B VZ VZ Temp IMIN e IR rz en VZ Time Average Temperature Coefficient Minimum Operating Current Reverse Breakdown Voltage Chang with Current Reverse Dynamic Impedance Wide Band Noise (RMS) Long Term Stability LM385/385B-1.2 Min. Typ. Max. Test Conditions IMIN IR IMAX IMIN IR IMAX IR = 100A 1.205 1.223 VZ IMIN IR 1mA 1mA IR 20mA IR = 100A IR = 100A, 10Hz f 10kHz IR = 100A, TA = 25C 0.1C Units 1.235 1.235 20 1.260 1.247 V V ppm/C 8 15 1.5 20 A mV mV V ppm/kHr 1 60 20 LM385/385B-2.5 Parameter Reverse Breakdown Voltage Symbol LM385 LM385B Average Temperature Coefficient Minimum Operating Current Reverse Breakdown Voltage Chang with Current Reverse Dynamic Impedance Wide Band Noise (RMS) Long Term Stability VZ VZ Temp IMIN e IR rz en VZ Time LM385/385B-2.5 Min. Typ. Max. Test Conditions IMIN IR IMAX IMIN IR IMAX IR = 100A 2.425 2.462 VZ IMIN IR 1mA 1mA IR 20mA IR = 100A, f = 20Hz IR = 100A, 10Hz f 10kHz IR = 100A, TA = 25C 0.1C Units 2.500 2.500 20 2.575 2.538 V V ppm/C 13 20 2 20 A mV mV V ppm/kHr 1 120 20 GRAPH / CURVE INDEX Characteristic Curves LM385/385B-1.2 Characteristic Curves LM385/385B-2.5 FIGURE # FIGURE # 1. RESPONSE TIME 8. RESPONSE TIME 2. REVERSE CHARACTERISTICS 9. REVERSE CHARACTERISTICS 3. FORWARD CHARACTERISTICS 10. FORWARD CHARACTERISTICS 4. TEMPERATURE DRIFT 11. TEMPERATURE DRIFT 5. REVERSE VOLTAGE CHANGE 12. REVERSE DYNAMIC IMPEDANCE 6. REVERSE DYNAMIC IMPEDANCE 13. NOISE VOLTAGE 7. NOISE VOLTAGE Copyright (c) 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 R O D U C T I O N D A T A S H E E T 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 1.5V TA = 0 to 70C 1.0V VIN 0.5V 36k Reverse Current - (A) Output Voltage 100 VOUT Input Voltage 0 5V 10 1 0 0.1 0 50 100 500 0 550 0.2 0.4 Time - (s) 0.8 1.0 1.2 1.4 Reverse Voltage - (V) FIGURE 3. -- FORWARD CHARACTERISTICS FIGURE 4. -- TEMPERATURE DRIFT 1.242 1.2 IR = 100A TA = 25C 1.24 Reference Voltage - (V) Forward Voltage - (V) 0.6 0.8 0.4 1.238 1.236 1.234 1.232 1.23 1.228 0 0.01 1.226 0.1 1 10 Forward Current - (mA) 4 100 0 10 20 30 40 50 60 70 Temperature - (C) Copyright (c) 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 R O D U C T I O N D A T A S H E E T 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 FIGURE 6. -- REVERSE DYNAMIC IMPEDANCE 16 1000 TA = 25C IR = 100A 12 TA = 0 to 70C Dynamic Impedance - () Output Voltage Change - (mV) 14 10 8 6 4 2 0 100 10 1 -2 -4 0.01 0.1 0.1 1 10 100 Reverse Current - (mA) 10 100 1k 10k 100k (f) Frequency - (Hz) FIGURE 7. -- NOISE VOLTAGE 800 (VN) Noise Voltage - (nV/ Hz) 700 600 500 400 300 200 100 10 IR = 100A TA = 25C 100 1k 10k 100k (f) Frequency - (Hz) Copyright (c) 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 R O D U C T I O N D A T A S H E E T 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 9. -- REVERSE CHARACTERISTICS TA = 25C 2.0V VIN 24K VOUT 0 Input Voltage TA = 25C 100 4.0V Reverse Current - (A) Output Voltage FIGURE 8. -- RESPONSE TIME 10 1 5 0 0.1 0 1.0 Time - (100s/Div.) 2.0 3.0 4.0 5.0 Reverse Voltage - (V) FIGURE 10. -- FORWARD CHARACTERISTICS FIGURE 11. -- TEMPERATURE DRIFT 1.0 2.52 TA = 25C 2.515 Reference Voltage - (V) Forward Voltage - (V) 0.8 0.6 0.4 2.51 2.505 2.5 2.495 2.49 0.2 2.485 0 0.001 0.01 0.1 1 Forward Current - (mA) 6 10 100 2.48 -40 20 0 20 40 60 80 100 Temperature - (C) Copyright (c) 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 R O D U C T I O N D A T A S H E E T 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 FIGURE 13. -- NOISE VOLTAGE 100 (VN) Noise Voltage - (nV/ Hz) Dynamic Impedance - () TA = 25C IR = 100A 10 1 1800 1500 1200 900 600 300 0.1 10 100 1k 10k (f) Frequency - (Hz) Copyright (c) 1996 Rev. 1.2 7/96 100k 10 IR = 100A TA = 25C 100 1k 10k 100k (f) Frequency - (Hz) 7