LTC V, 0mA Flash Memory Programming Supply FEATRES Guaranteed 0mA Output Regulated V ±% Output Voltage No Inductors Supply Voltage Range:.V to.v I CC 0.µA Typ in Shutdown Low Power: I CC = 00µA -Pin SO Package Same Pinout as LTC and MAX APPLICATIONS V Flash Memory Programming Supplies Compact V Op Amp Supplies Battery-Powered Systems DESCRIPTION The LTC is a regulated V, 0mA output DC/DC converter. It provides the V ±% output necessary to program double byte-wide flash memories. The output provides 0mA from input voltages as low as.v without using any inductors. Only four external capacitors are required to complete an extremely small, surface mountable circuit. The output can be momentarily shorted to ground without damaging the part. The active high TTL compatible Shutdown pin can be directly connected to a microprocessor. In the shutdown mode, the supply current typically drops to 0.µA. The LTC is available in an -pin SO package., LTC and LT are registered trademarks of Linear Technology Corporation. TYPICAL APPLICATION Flash Memory Programming Supply Output Voltage vs Load.V TO.V.0. C C C C LTC ON V V VPP LTC TA0 µp FLASH MEMORY OTPT VOLTAGE (V)....0.....0 0 0 0 0 0 00 LOAD CRRENT (ma) LTC TA0
LTC ABSOLTE MAXIMM RATINGS (Note ) W W W Supply Voltage (V DD )... V Input Voltage ()... 0.V to 0.V I OT Continuous... 90mA Operating Temperature Range... 0 C to 0 C Storage Temperature Range... C to 0 C Lead Temperature (Soldering, 0 sec)... 00 C PACKAGE/ORDER INFORMATION C C C C TOP VIEW S PACKAGE -LEAD PLASTIC SO T JMAX = C, θ JA = 0 C/ W W ORDER PART NMBER LTCCS Consult factory for Industrial and Military grade parts and TSSOP package option. ELECTRICAL CHARACTERISTICS.V.V, T A = 0 C to 0 C (Notes, ). SYMBOL PARAMETER CONDITIONS MIN TYP MAX NITS Output Voltage 0mA I OT 0mA, V = 0V.. V I CC Supply Current No Load, V = 0V 0..0 ma I Shutdown Supply Current No Load, V = 0. 0 µa f OSC Oscillator Frequency = V, I OT = 0mA 00 khz Power Efficiency = V, I OT = 0mA % R SW to Switch Impedance = V = V, I OT = 0mA 0. kω V IH Input High Voltage. V V IL Input Low Voltage 0. V Input Current = V, V = 0V 0 0 µa = V, V = V 0 0 0 µa t ON Turn-On Time C = C =, C = C = (Note ) (Figures, ) 00 µs t OFF Turn-Off Time C = C =, C = C = (Figures, ) 0 ms The denotes specifications which apply over the full operating temperature range. Note : Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note : 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 : All typicals are given at = V, T A = C. Note : A higher value output capacitor can be used but the turn-on and turn-off time will increase proportionally.
TYPICAL PERFORMANCE CHARACTERISTICS W LTC Supply Current I OT = 0 Output Voltage. = V. Supply Current 0 I OT = 0mA SPPLY CRRENT (µa) 0 = V OTPT VOLTAGE (V)...0.. I OT = 0mA I OT = 0mA IOT = 90mA SPPLY CRRENT (ma) 0 0 00 9 90 =.V = V =.V. TEMPERATRE ( C) 0. TEMPERATRE ( C) 0 0 TEMPERATRE ( C) 0 LTC TPC0 LTC TPC0 LTC TPC0 Output Voltage. T A = C. 0 0 Oscillator Frequency OTPT VOLTAGE (V)...0.. I OT = 0mA, 0mA I OT = 90mA FREQENCY (khz) 0 0 00 0 0. 0....9.0.... SPPLY VOLTAGE (V). 0 TEMPERATRE ( C) 0 LTC TPC0 LTC TPC0 PIN FNCTIONS C (Pin ): First Charge Capacitor Negative Input. Connect a capacitor (C) between C and C. C (Pin ): First Charge Capacitor Positive Input. Connect a capacitor (C) between C and C. C (Pin ): Second Charge Capacitor Negative Input. Connect a capacitor (C) between C and C. C (Pin ): Second Charge Capacitor Positive Input. Connect a capacitor (C) between C and C. (Pin ): Positive Supply Input..V.V. Requires a bypass capacitor to ground (C). (Pin ): V Output. Requires a or a higher value bypass capacitor to ground (C). = when in the shutdown mode. (Pin ): Ground. (Pin ): Active-High TTL Logic Level Shutdown Pin. is internally pulled up to. Connect to for normal operation. In shutdown mode, the charge pump is turned off and =.
.V LTC BLOCK DIAGRAM W C SA SC S R C IN C C SA C SB SC R V DIV C OT C C SB CLK V BGAP BANDGAP REFERENCE R SD OSCILLATOR S CHARGE PMP LTC BD S AND S SHOWN WITH PIN LOW. SA, SB, SC, SD, SA, SB AND SC SHOWN CHARGING C AND C WITH OSCILLATOR OTPT LOW AND V DIV < V BGAP V HYST. AT OSCILLATOR OTPT HIGH, SA, SB, SC AND SD OPEN WHILE SA, SB AND SC CLOSE TO CHARGE. COMPARATOR HYSTERESIS IS ±V HYST TIMING DIAGRAMS W W t OFF t ON V V.V.V Figure. Timing Diagram 0V LTC F0 C = C C V C = C C LTC C = C =.V TO.V LTC F0 Figure. Timing Circuit
OPERATION LTC The LTC uses a charge pump tripler to generate V from a of V. The charge pump is clocked by an internal oscillator. The oscillator frequency is not critical and may vary from the typical value of 00kHz. When the oscillator output is low, C and C are each connected between and, charging them to (see Figure ). When the oscillator output goes high, C and C are stacked in series with the bottom plate of C pulled to (see Figure ). The top plate of C is switched to charge C OT, which enables to rise. is regulated to within % of V by an oscillator pulse gating scheme that turns the charge pump on and off based on the comparator results of and a reference voltage. First, a resistor divider senses ; if the output of the divider (V DIV ) is less than the output of a bandgap (V BGAP ) by the hysteresis voltage (V HYST ) of the comparator, then oscillator pulses are applied to the charge pump to raise. When V DIV is above V BGAP by V HYST, the oscillator pulses are prevented from clocking the charge pump. As a result, drops until V DIV is below V BGAP by V HYST again. To ensure proper start-up when is lower than and maintain proper operation when is higher than, the gates of all internal switches are driven between and the higher of either or. To reduce supply current, the LTC may be put into shutdown mode by floating the pin or connecting it to. In this mode, the bandgap, comparator, oscillator and resistor divider are switched off to reduce the supply current to typically 0.µA. At the same time an internal switch shorts to ; takes 0ms (typ) to reach.v (see t OFF in Figure ). When the pin is low, the LTC exits shutdown and the charge pump operates to raise to V. takes 00µs (typ) to reach the lower regulation limit of.v (see t ON in Figure ). C OT C C C C LTC F0 LTC F0 Figure. C and C Charge to Figure. C and C Stacked in Series with C Tied to APPLICATIONS INFORMATION Choice of Capacitors W The LTC is tested with the capacitors shown in Figure. C and C are ceramic capacitors and C IN and C OT are tantalum capacitors. Refer to Table if other choices are desired. Table. Recommended Capacitor Types and Values CAPACITOR CERAMIC TANTALM ALMINM C, C to µf Not Recommended Not Recommended C OT (Min) (Min) (Min) C IN (Min) (Min) (Min) C and C should be ceramic capacitors with values in the range of to µf. Higher values provide better load regulation. Tantalum capacitors are not recommended as the higher ESR of these capacitors degrades performance at high load currents and =.V. C IN and C OT can be ceramic, tantalum or electrolytic capacitors. The ESR of C OT introduces steps in the waveform whenever the charge pump charges C OT. This tends to increase ripple. Ceramic or tantalum capacitors are recommended for C OT if minimum ripple is
LTC APPLICATIONS INFORMATION W desired. (The LTC does not require a 0.µF capacitor between and for stability.) Besides using it to program flash memories, the LTC can also provide multiple supply voltages with the help of two diodes and two capacitors. Output voltages of 9V and V can easily be obtained. In other words, the LTC can power dual supply (±V) and single supply (V) op amps. TYPICAL APPLICATIONS Dual Voltage Supply Output at V and 9V Dual Supply Voltage Output at V and V C C C C LTC = V IN* C C C C LTC = V µf.v TO.V N* *FOR LOWER VOLTAGE DROP, SE SCHOTTKY DIODES ** MST PLL MORE CRRENT OT OF THAN V V = 9V** µf LTC TA0 µf IN* V = V** N* µf.v TO.V LTC TA0 * FOR LOWER VOLTAGE DROP, SE SCHOTTKY DIODES ** MST PLL MORE CRRENT OT OF THAN V Gain of 0 Amplifier sing LT 00 Powered by LTC C C C C LTC 0k = V V IN (V) LT00 90.k (V IN )(0) µf N*.V TO.V N* ( V)** µf LTC TA0 *FOR LOWER VOLTAGE DROP, SE SCHOTTKY DIODES ** MST PLL MORE CRRENT OT OF THAN V
LTC TYPICAL APPLICATIONS Dual Voltage Supply Output at V and V FROM µp C C C C LTC *. TO.V V * * BOOST C V OSC LTC 00pF LTC TA0 C *CD00 OR OTHER HIGH VOLTAGE INVERTER V PACKAGE DESCRIPTION Dimensions in inches (millimeters) unless otherwise noted. S Package -Lead Plastic Small Outline (Narrow 0.0) (LTC DWG # 0-0-0) 0.9 0.9* (.0.00) 0. 0. (.9.9) 0.0 0.** (.0.9) 0.00 0.00 (0.0 0.) 0.00 0.00 (0. 0.0) 0 TYP 0.0 0.09 (..) 0.00 0.00 (0.0 0.) 0.0 0.00 0.0.0 *DIMENSION DOES NOT INCLDE MOLD FLASH. MOLD FLASH SHALL NOT EXCEED 0.00" (0.mm) PER SIDE ** DIMENSION DOES NOT INCLDE INTERLEAD FLASH. INTERLEAD FLASH SHALL NOT EXCEED 0.00" (0.mm) PER SIDE 0.0 0.09 (0. 0.) 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. 0.00 (.0) BSC SO 09
LTC TYPICAL APPLICATION V to.v/a Converter with V/0mA Auxiliary Output SHTDOWN 0Ω 00pF 0.µF C C LTC C V OT C 0 V IN I TH C T 0pF S LTC-. P DRIVE SENSE SENSE N DRIVE P k 000pF V 0mA TP00 VN 00Ω 00Ω *PANASONIC BCGCOKB0R OR EQIVALENT Burst Mode IS A TRADEMARK OF LINEAR TECHNOLOGY CORPORATION. Si0DY Si0DY Burst Mode TM OPERATION DEFEAT; SE IF REQIRED µh 0A MBRS0T 0µF* V 0.0Ω W V IN V.V A 0µF.V 0S-CON LTC TA0 RELATED PARTS PART NMBER DESCRIPTION COMMENTS LTC0A V CMOS Voltage Converter.V to V Supply Range, 9% Efficiency, ± LT0/LT0/LT0 Micropower DC/DC Converter, V and V Adjustable from V IN = V, se Inductor LTC V, 0mA Flash Memory Program Supply / Source Current as LTC, Cannot Short to LT0/LT0/LT0 Micropower High Efficiency V/V, DC/DC Converter V at 00mA or V at 0mA, se Inductor LT Single PCMCIA VPP Driver/Regulator 0mA Output, Current Limit, Thermal Shutdown LTC9 Regulating Positive to Negative Charge Pump Fixed.V or Adjustable Output, No Inductors Linear Technology Corporation 0 McCarthy Blvd., Milpitas, CA 90- (0) -900 FAX: (0) -00 TELEX: 99-9 www.linear-tech.com f LT/MP 09 K PRINTED IN SA LINEAR TECHNOLOGY CORPORATION 99