LT1029/LT1029A 5V Bandgap Reference U FEATURES ■ ■ ■ ■ ■ ■ ■ DESCRIPTIO 0.2% Output Tolerance 0.6Ω Shunt Impedance 700µA to 10mA Operating Current Pin Compatible with LM136-5 20ppm/°C Max Drift Output Voltage Trim does not Affect Drift Can be Used as Positive or Negative Reference U APPLICATIO S ■ ■ ■ ■ The LT ®1029 is a 5V bandgap reference intended for use in the shunt or “Zener” mode, allowing it to be used as either a positive or negative reference. The output is pretrimmed to ± 0.2% accuracy with 20ppm/°C maximum temperature drift. A trim pin allows additional output adjustment for even more precise output voltage. Operating current range for the LT1029 is 700µA to 10mA. Extremely low dynamic impedance allows excellent output regulation even with fluctuating operating current. The LT1029 will replace an LM136-5 or LM336-5 and simplify circuits using the “minimum temperature coefficient” trim network. The LT1029 does not require this special network to meet its temperature drift specification; these application network components are simply removed. If output trimming is required for initial accuracy, the diodes in the trim network should be replaced with jumpers. A-to-D and D-to-A Converters Precision Regulators Precision Current Sources V to F and F to V Converters , LTC and LT are registered trademarks of Linear Technology Corporation. U TYPICAL APPLICATIO Output Voltage Drift 5.015 15V R1 10k 5V LT1029 LT1029 –5V R2 10k –15V OUTPUT VOLTAGE (V) 5.010 5.005 5.000 4.995 4.990 LT1029 • TA01 4.895 –50 –25 0 25 50 75 TEMPERATURE (°C) 100 125 LT1029 • TA02 1029afa 1 LT1029/LT1029A W W W AXI U U ABSOLUTE RATI GS (Note 1) Reverse Current .................................................... 15mA Forward Current ................................................... 10mA Operating Temperature Range LT1029C/LT1029AC ............................... 0°C to 70°C LT1029M/LT1029AM (OBSOLETE) ....– 55°C to 125°C Storage Temperature ............................ – 65°C to 150°C Lead Temperature (Soldering, 10 sec).................. 300°C U U W PACKAGE/ORDER I FOR ATIO ORDER PART NUMBER BOTTOM VIEW ADJ + ORDER PART NUMBER BOTTOM VIEW LT1029AMH LT1029MH LT1029ACH LT1029CH – H PACKAGE TO-46 METAL CAN TJMAX = 150°C, θJA = 440°C/W, θJC = 80°C/W ADJ + LT1029ACZ LT1029CZ – Z PACKAGE TO-92 PLASTIC TJMAX = 100°C, θJA = 160°C/W OBSOLETE PACKAGE Consider the Z Package as an Alternate Source Consult LTC Marketing for parts specified with wider operating temperature ranges. ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are TA = 25°C. PARAMETER CONDITIONS MIN TYP MAX UNITS Reverse Breakdown Voltage IR = 1mA 4.99 4.95 5.00 5.00 5.01 5.05 V V Reverse Breakdown Change with Current 700µA ≤ IR ≤ 10mA ● 2 3 5 8 mV mV ● 0.2 0.3 0.6 1.0 Ω Ω LT1029AC LT1029C LT1029AM LT1029M ● ● ● ● 3 5 7 10 7 12 18 36 mV mV mV mV LT1029AM/LT1029AC LT1029C LT1029M ● ● ● 8 12 15 20 34 40 ppm/°C ppm/°C ppm/°C Reverse Dynamic Impedance Temperature Stability Equivalent Temperature Drift LT1029AM/LT1029AC LT1029M/LT1029C IR = 1mA IR = 1mA Long Term Stability Trim Range 20 ±3 + 5, – 13 ppm/kHr % Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. 1029afa 2 LT1029/LT1029A U W TYPICAL PERFOR A CE CHARACTERISTICS Reverse Characteristics 1.0 0.9 0.8 CURRENT (mA) 0.7 0.6 0.5 TJ = 25°C 0.4 0.3 TJ = 125°C 0.2 TJ = – 55°C 0.1 0 7 6 4 1 3 2 5 OUTPUT TO GROUND VOLTAGE (V) 0 8 LT1029 • TPC01 U W U U APPLICATIO S I FOR ATIO Output Trimming Output voltage trimming on the LT1029 is nominally accomplished with a potentiometer connected from output to ground with the wiper tied to the trim pin. The LT1029 was made compatible with existing references, so the trim range is large; 5%, – 13%. This large trim range makes precision trimming rather difficult. One solution is to insert resistors in series with both ends of the potentiometer. This has the disadvantage of potentially poor tracking between the fixed resistors and the potentiometer. A second method of reducing trim range is to insert a resistor in series with the wiper of the potentiometer. This works well only for a very small trim range because of the mismatch in TCs between the series resistor and the internal thin film resistors. These film resistors can have a TC as high as 500ppm/°C. That same TC is then transferred to the change in output voltage; a 1% shift in output voltage causes a (500ppm) (1%) = 5ppm/°C change in output voltage drift. The worst case error in initial output voltage for the LT1029A is 0.2% and the LT1029 is 1%, so a series resistor is satisfactory if the output is simply trimmed to nominal value. 1ppm/°C TC shift would be the maximum expected for the LT1029A and 5ppm/°C for the LT1029. transient in operating current. A 1µF solid tantalum capacitor is suggested for most situations where bypassing is desirable. Wide Trim Range (5%, – 13%) V+ I ≥ 900µA VREF 25k LT1029 • AI01 Narrow Trim Range V+ I ≥ 800µA VREF = 5.000V R1* 100k LT1029 • TA02 TRIM RANGE 0.4% – LT1029A, R1 = 750k 1.2% – LT1029, R1 = 250k Trimming Output to 5.120V V+ I ≥ 800µA VREF = 5.120V R1 41.2k Shunt Capacitance R2 5k The LT1029 is stable with all values of shunt capacitance, but values between 300pF and 0.01µF are not recommended because they cause longer settling following a R3 4.02k LT1029 • AI03 1029afa Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights. 3 LT1029/LT1029A U W U U APPLICATIO S I FOR ATIO Split ± 2.5V References 2.5V R1 25k 0.1% LT1029 5V – LT1001 R2 25k 0.1% + – 5V – 2.5V R3 1k 5% – 5V LT1029 • AI04 U PACKAGE DESCRIPTIO H Package 2-Lead and 3-Lead TO-46 Metal Can (Reference LTC DWG # 05-08-1340) .209 – .219 (5.309 – 5.537) .178 – .195 (4.521 – 4.953) REFERENCE PLANE .050 (1.270) TYP .085 – .105 (2.159 – 2.667) .100 (2.540) TYP .050 (1.270) TYP PIN 1 .500 (12.700) MIN FOR 3-LEAD PACKAGE ONLY .025 (0.635) MAX .016 – .019** (0.406 – 0.483) DIA SEATING* PLANE 45° .036 – .046 (0.914 – 1.168) .028 – .048 (0.711 – 1.219) H02/03(TO-46) 0801 *LEAD DIAMETER IS UNCONTROLLED BETWEEN THE REFERENCE PLANE AND .050" BELOW THE REFERENCE PLANE .016 – .024 **FOR SOLDER DIP LEAD FINISH, LEAD DIAMETER IS (0.406 – 0.610) OBSOLETE PACKAGE Z Package 3-Lead Plastic TO-92 (Similar to TO-226) (Reference LTC DWG # 05-08-1330) .060 ± .005 (1.524± 0.127) DIA .060 ± .010 (1.524 ± 0.254) .180 ± .005 (4.572 ± 0.127) .90 (2.286) NOM .180 ± .005 (4.572 ± 0.127) 3 2 .140 ± .010 (3.556 ± 0.127) 1 5° NOM 10° NOM .500 (12.70) MIN .050 UNCONTROLLED (1.270) LEAD DIMENSION MAX .015 ± .002 (0.381 ± 0.051) TO-92 TAPE AND REEL REFER TO TAPE AND REEL SECTION OF LTC DATA BOOK FOR ADDITIONAL INFORMATION Z3 (TO-92) 0801 .050 (1.27) BSC .016 ± .003 (0.406 ± 0.076) .098 +.016/–.04 (2.5 +0.4/–0.1) 2 PLCS 1029afa 4 Linear Technology Corporation LT/TP 1102 1K REV A • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com LINEAR TECHNOLOGY CORPORATION 1985