LTC1262 12V, 30mA Flash Memory Programming Supply U DESCRIPTIO FEATURES ■ ■ ■ ■ ■ ■ ■ Regulated 12V ±5% Output Voltage No Inductors Supply Voltage Range: 4.75V to 5.5V Guaranteed 30mA Output Low Power: ICC = 500µA ICC in Shutdown: 0.5µA 8-Pin PDIP or SO-8 Package The LTC®1262 is a regulated 12V, 30mA output DC/DC converter. It is designed to provide the 12V ±5% output necessary to program byte-wide flash memories. The output will provide up to 30mA from input voltages as low as 4.75V without using any inductors. Only four external capacitors are required to complete an extremely small surface mountable circuit. The TTL compatible shutdown pin can be directly connected to a microprocessor and reduces the supply current to less than 0.5µA. The LTC1262 offers improved shutdown current performance and requires fewer external components than competing solutions. UO APPLICATI ■ ■ ■ S 12V Flash Memory Programming Supplies Compact 12V Op Amp Supplies Battery-Powered Systems The LTC1262 is available in an 8-pin PDIP or SO-8 package. , LTC and LT are registered trademarks of Linear Technology Corporation. UO TYPICAL APPLICATI In/Out of Shutdown 1 C1– SHDN 2 C1+ GND 8 FROM MPU 0.22µF 7 LTC1262 3 0.22µF 4 C2 – C2+ VOUT VCC 6 5 + FLASH MEMORY 4.7µF SHDN 5V 5V/DIV 0V VPP + 4.7µF 12V VCC VCC 4.75V TO 5.5V LTC1262 • TA01 VOUT 5V/DIV 5V 0V 1ms/DIV 1262 TA01a 1 LTC1262 U U RATI GS W W W W AXI U U ABSOLUTE PACKAGE/ORDER I FOR ATIO (Note 1) Supply Voltage (VCC) ................................................ 6V Input Voltage (SHDN) ................... – 0.3V to V CC + 0.3V Output Current (IOUT) ........................................... 50mA Operating Temperature Range LTC1262C................................................ 0°C to 70°C LTC1262I........................................... – 40°C to 85°C Storage Temperature Range ................ – 65°C to 150°C Lead Temperature (Soldering, 10 sec)................. 300°C ORDER PART NUMBER TOP VIEW C1– 1 8 SHDN C1+ 2 7 GND – 3 6 VOUT C2 + 4 5 VCC C2 N8 PACKAGE 8-LEAD PDIP S8 PACKAGE 8-LEAD PLASTIC SO LTC1262CN8 LTC1262CS8 LTC1262IS8 S8 PART MARKING TJMAX = 150°C, θJA = 100°C/W (N8) TJMAX = 150°C, θJA = 150°C/W (S8) 1262 1262I Consult factory for Military grade parts. ELECTRICAL CHARACTERISTICS VCC = 4.75V to 5.5V, TA = – 40°C to 85°C, (Notes 2, 3), unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN VOUT Output Voltage 0mA ≤ IOUT ≤ 30mA, VSHDN = 0V, 0°C ≤ TA ≤ 70°C 0mA ≤ IOUT ≤ 30mA, VSHDN = 0V, – 40°C ≤ TA ≤ 85°C ● ● ICC Supply Current No Load, VSHDN = 0V, 0°C ≤ TA ≤ 70°C No Load, VSHDN = 0V, – 40°C ≤ TA ≤ 85°C ● ● ISHDN Shutdown Supply Current No Load, VSHDN = VCC fOSC Oscillator Frequency TYP MAX UNITS 12.6 12.6 V V 0.5 0.5 1.0 1.3 mA mA ● 0.5 10 µA VCC = 5V, IOUT = 30mA ● 300 kHz Power Efficiency VCC = 5V, IOUT = 30mA ● 74 % RSW VCC to VOUT Switch Impedance VCC = VSHDN = 5V, IOUT = 0mA ● 0.18 VIH SHDN Input High Voltage ● VIL SHDN Input Low Voltage ● 11.4 11.2 2 2.4 kΩ V 0.8 V –5 –5 10 µA µA µA SHDN Input Current VCC = 5V, VSHDN = 0V, 0°C ≤ TA ≤ 70°C VCC = 5V, VSHDN = 0V, – 40°C ≤ TA ≤ 85°C VCC = 5V, VSHDN = 5V tON Turn-On Time C1 = C2 = 0.22µF, CIN = COUT = 4.7µF, (Figures 1, 2) 500 µs tOFF Turn-Off Time C1 = C2 = 0.22µF, CIN = COUT = 4.7µF, (Figures 1, 2) 3.3 ms The ● denotes specifications which apply over the full operating temperature range. Note 1: Absolute maximum ratings are those values beyond which the life of the device may be impaired. 2 ● ● ● – 20 –35 – 10 –10 0.06 Note 2: All currents into device pins are positive; all currents out of device pins are negative. All voltages are referenced to ground unless otherwise specified. Note 3: All typicals are given at VCC = 5V, TA = 25°C. LTC1262 U W TYPICAL PERFORMANCE CHARACTERISTICS Shutdown Supply Current vs Temperature Efficiency vs Output Current 85 3.6 EFFICIENCY (%) 80 SHUTDOWN SUPPLY CURRENT (µA) VCC = 4.75V VCC = 5V 75 VCC = 5.5V 70 65 60 55 0 10 3.0 2.4 1.8 1.2 0.6 0 –50 50 20 30 40 OUTPUT CURRENT (mA) VCC = 5V –25 0 25 50 TEMPERATURE (°C) LTC1262 G01 Supply Current vs Supply Voltage Output Voltage vs Output Current 12.2 IOUT = 0 12.0 580 560 540 520 TA = 25°C TA = 0°C 4.75 5.0 5.25 5.5 SUPPLY VOLTAGE (V) 11.6 VCC = 5.5V 11.4 VCC = 5V 11.2 11.0 10.8 10.6 500 4.5 VCC = 4.75V 11.8 TA = 70°C OUTPUT VOLTAGE (V) SUPPLY CURRENT (µA) 100 LTC1262 G02 600 480 75 10.4 5.75 6.0 10.2 0 5 10 15 20 25 30 35 40 45 50 OUTPUT CURRENT (mA) LTC1262 G03 1262 G04 U U U PI FU CTIO S C1 – (Pin 1): C1 Negative Input. Connect a 0.22µF capacitor C1 between C1+ and C1 –. C1 + (Pin 2): C1 Positive Input. Connect a 0.22µF capacitor C1 between C1+ and C1–. C2 – (Pin 3): C2 Negative Input. Connect a 0.22µF capacitor C2 between C2 + and C2 –. C2+ (Pin 4): C2 Positive Input. Connect a 0.22µF capacitor C2 between C2 + and C2 –. VCC (Pin 5): Positive Supply Input Where 4.75V ≤ VCC ≤ 5.5V. Connect a 4.7µF bypass capacitor CIN to ground. VOUT (Pin 6): 12V Output. Connect a 4.7µF bypass capacitor COUT to ground. When in the shutdown mode VOUT = VCC. GND (Pin 7): Ground. SHDN (Pin 8): Logic Level Shutdown Pin. Application of a logic low at SHDN pin will place the regulator in normal operation. With no external connection, or with SHDN tied to VCC, the device will be put into shutdown mode. Connect to GND for normal operation. In shutdown mode the charge pump is turned off and VOUT = VCC. 3 LTC1262 W BLOCK DIAGRAM VCC + S3A S3C CIN R1 C1+ D1 S1 SHDN D2 S4A C1 VOUT + C1 – S3B – C2+ + S4B C2 COUT R2 VDIV R3 BANDGAP REFERENCE VBGAP S2 C2 – S3D OSCILLATOR CHARGE PUMP GND LTC1262 • BD S1 AND S2 SHOWN WITH SHDN PIN LOW. S3A, S3B, S3C, S3D, S4A AND S4B SHOWN WITH OSCILLATOR OUTPUT LOW AND VDIV < VBGAP – VHYST. COMPARATOR HYSTERISIS IS ±VHYST. WU W TI I G DIAGRA S t OFF t ON VOUT 11.4V VOUT VCC VCC 1.4V 1.4V 0V LTC1262 • F01 Figure 1. LTC1262 Timing Diagram 4 1 C1– SHDN 2 C1+ GND 3 C2 – 8 C2 0.22µF 4 C2+ VOUT VCC VSHUTDOWN 7 LTC1262 5.1V VSHDN C1 0.22µF 6 5 + COUT 4.7µF + CIN 4.7µF VCC 4.75V TO 5V Figure 2. LTC1262 Timing Circuit VOUT LTC1262 • F02 LTC1262 U W U U APPLICATIONS INFORMATION Operation Choice of Capacitors The LTC1262 uses a charge pump tripler to generate 12V from a VCC of 5V. The charge pump operates when clocked by a 300kHz oscillator. When the oscillator output is low, C1 and C2 are connected between VCC and GND, charging them to VCC. When the oscillator output goes high, C1 and C2 are stacked in series with the bottom plate of C1 pulled to VCC. The top plate of C2 is switched to charge COUT and VOUT rises. VOUT is regulated to within 5% of 12V by an oscillator pulse gating scheme. A resistor divider senses VOUT. When the output of the divider (VDIV) is less than the output of a bandgap (VBGAP) by the hysteresis voltage (VHYST) of the comparator, oscillator pulses are applied to the charge pump to raise VOUT. When VDIV is above VBGAP by VHYST, the oscillator pulses are prevented from clocking the charge pump. VOUT drops until VDIV is below VBGAP by VHYST again. The gates of all internal switches are driven between VOUT and GND. An internal diode ensures that the LTC1262 will start up under load by charging COUT to one diode drop below VCC. The LTC1262 is tested with the capacitors shown in Figure 2. C1 and C2 are 0.22µF ceramic capacitors and CIN and COUT are 4.7µF tantalum capacitors. Refer to Table 1 if other choices are desired. To reduce supply current the LTC1262 may be put into shutdown mode by floating the SHDN pin or taking it to VCC. In this mode the bandgap, comparator, oscillator and resistor divider are switched off to reduce supply current to typically 0.5µA. At the same time an internal switch shorts VOUT to VCC; VOUT takes 3.3ms to reach 5.1V (see tOFF in Figure 1). When the SHDN pin is low, the LTC1262 exits shutdown and the charge pump operates to raise VOUT to 12V. VOUT takes 500µs to reach the lower regulation limit of 11.4V (see tON in Figure 1). Table 1. Recommended Capacitor Types and Values CAPACITOR CERAMIC TANTALUM ALUMINUM C1, C2 0.22µF to 1µF Not Recommended Not Recommended COUT 2µF (Min) 4.7µF (Min) 10µF (Min) CIN 1µF (Min) 4.7µF (Min) 10µF (Min) C1 and C2 should be ceramic capacitors with values in the range of 0.22µF to 1µF. Higher values provide better load regulation. Tantalum capacitors are not recommended as the higher ESR of these capacitors degrades performance when the load current is above 25mA with VCC = 4.75V. CIN and COUT can be ceramic, tantalum or electrolytic capacitors. The ESR of COUT introduces steps in the VOUT waveform whenever the charge pump charges COUT. This tends to increase VOUT ripple. Ceramic or tantalum capacitors are recommended for COUT if minimum ripple is desired. The LTC1262 does not require a 0.1µF capacitor between VCC and VOUT for stability. Maximum Load Current The LTC1262 will source up to 50mA continuously without any damage to itself. Do not short the VOUT pin to ground. If the VOUT pin is shorted to ground, irreversible damage to the device will result. 5 LTC1262 UO TYPICAL APPLICATI 5V to 3.3V/10A Converter C7 0.22µF C8 0.22µF 1 C1– 2 C1+ 3 C2 – 4 C2+ SHDN U2 LTC1262 GND VOUT VCC 8 7 6 + C9 1µF 5 + Q1 TP0610 U1 LTC1148-3.3 3 C6 10µF 25V + 10 SHUTDOWN 6 R1 510Ω C1 3300pF 4 C2 150pF 11 PDRIVE SHDN 8 SENSE + ITH 7 SENSE – CT NDRIVE PGND Q4 Si9410 L2 3µH/10A 1 VIN SGND Q3 Si9410 Q2 VN7002 R2 100Ω C3 1000pF + R4 0.01Ω 2W R3 100Ω 14 VOUT 3.3V 10A + Q5 Si9410 D1 MBRS120T3 + C5 330µF 6.3V ×2 OS-CON 12 R6 TM 22k Burst Mode DEFEAT; USE IF REQUIRED Burst Mode is a trademark of Linear Technology Corporation. 6 + VIN 5V C4 220µF 8V ×3 PANASONIC ECGCOKB220R LTC1262 • TA02 LTC1262 U PACKAGE DESCRIPTION Dimensions in inches (millimeters) unless otherwise noted. N8 Package 8-Lead PDIP (Narrow 0.300) (LTC DWG # 05-08-1510) 0.400* (10.160) MAX 8 7 6 5 1 2 3 4 0.255 ± 0.015* (6.477 ± 0.381) 0.300 – 0.325 (7.620 – 8.255) 0.065 (1.651) TYP 0.009 – 0.015 (0.229 – 0.381) ( +0.035 0.325 –0.015 8.255 +0.889 –0.381 0.130 ± 0.005 (3.302 ± 0.127) 0.045 – 0.065 (1.143 – 1.651) ) 0.125 (3.175) 0.020 MIN (0.508) MIN 0.018 ± 0.003 (0.457 ± 0.076) N8 1197 0.100 ± 0.010 (2.540 ± 0.254) *THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.010 INCH (0.254mm) S8 Package 8-Lead Plastic Small Outline (Narrow 0.150) (LTC DWG # 05-08-1610) 0.189 – 0.197* (4.801 – 5.004) 8 7 6 5 0.150 – 0.157** (3.810 – 3.988) 0.228 – 0.244 (5.791 – 6.197) 1 0.010 – 0.020 × 45° (0.254 – 0.508) 0.008 – 0.010 (0.203 – 0.254) 0.053 – 0.069 (1.346 – 1.752) 0°– 8° TYP 0.016 – 0.050 0.406 – 1.270 0.014 – 0.019 (0.355 – 0.483) 2 3 4 0.004 – 0.010 (0.101 – 0.254) 0.050 (1.270) TYP *DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE **DIMENSION DOES NOT INCLUDE INTERLEAD FLASH. INTERLEAD FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE 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. SO8 0996 7 LTC1262 UO TYPICAL APPLICATI Output Voltage vs Output Current for Two Paralleled Devices Paralleling Devices C1– 2 + SHDN 8 0.22µF C1 GND 0.22µF 4 1 C2 – VOUT C2+ C1– VCC SHDN C1+ GND + 5 10µF 12V OUTPUT + 10µF VCC 4.75V TO 5.5V 8 7 0.22µF C2 – VOUT 4 C2+ VCC 11.8 VCC = 5.5V 11.6 11.4 VCC = 4.75V 11.2 11.0 10.8 10.6 LTC1262 3 VCC = 5V 12.2 12.0 6 0.22µF 2 12.4 7 LTC1262 3 TIE TO VCC OR FLOAT TO SHUTDOWN BOTH DEVICES OUTPUT VOLTAGE (V) 1 10.4 6 0 10 20 30 40 50 60 70 80 90 100 OUTPUT CURRENT (mA) 5 NOTE: KEEP DEVICES CLOSE TOGETHER OR USE SEPARATE 4.7µF TANTALUM CAPACITORS IF THIS IS NOT POSSBILE. 1262 TA04 SEE FIGURE AT LEFT. LTC1262 • TA03 RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LT1106* Micropower Step-Up DC/DC Converter for PCMCIA Card Flash Memory PCMCIA Card Power Control, 9µA ISHDN, Small SMT Components, Requires External Inductor LT1109-12 Micropower Low Cost DC/DC Converter Adjustable and Fixed 12V Three-Lead Z Package, Requires External Inductor LT1109A-12 Micropower DC/DC Converter Flash Memory VPP Generator Adjustable and Fixed 12V Requires External Inductor LT1301 Micropower High Efficiency 5V/12V Step-Up DC/DC Converter for Flash Memory 7µA ISHDN, SMT Inductor and Capacitors LT1309 500kHz Micropower DC/DC Converter for Flash Memory Small SMT Inductor and Capacitors, 6µA ISHDN * See also LT1312/LT1313 PCMCIA VPP drivers/regulators, LT1314/LT1315 PCMCIA switch matrix and the LTC1470/LTC1471/LTC1472 Protected VCC and VPP switching matrices 8 Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7417● (408)432-1900 FAX: (408) 434-0507● TELEX: 499-3977 ● www.linear-tech.com LT/TP 0298 REV A 2K • PRINTED IN USA LINEAR TECHNOLOGY CORPORATION 1994