FEATURES Ultralow Power: Icg = 6A Typ Short-Circuit/Thermal Protected 5V +4% Regulated Output Vin Range: 2.7V to 5V Output Current: 10MA (Vjy >= 2.7V) 20mA (Vin = 3V) No Inductors Ultrasmall Application Circuit (0.045in2) 800kHz Switching Frequency Available in 5-Pin SOT-23 APPLICATIONS Cellular Telephones Battery-Operated Equipment Local Power Supplies Handheld Instruments PCMCIA Supplies } \D LIC 1517-5 TECHNOLOGY Micropower, Regulated SV Charge Pump in a 5-Pin SOT-23 Package DESCRIPTION The LTC1517-5 is a micropower charge pump DC/DC converter that produces a regulated 5V output. The input voltage range is 2.7V to 5V. Extremely low operating current (typically 6uA with no load) and low external parts count (one 0.1p/F flying capacitor and two small bypass capacitors at Vj and Voyt) make the part ideally suited for small, light load battery-powered applications. The total printed circuit board area of the application circuit shown below is only 0.045in2. The part operates as a Burst Mode switched-capacitor voltage doubler to produce a regulated output. The part has thermal shutdown capability and can survive a continuous short circuit from Voyz to GND. The device is available in a 5-pin SOT-23 package. I, LTC and LT are registered trademarks of Linear Technology Corporation. Burst Mode is a trademark of Linear Technology Corporation. TYPICAL APPLICATION 0.1 pF vj Vout =5V+4% N 2.7V T0 5V lout = 10MA (Vin = 2.7V) lout = 20mA (Vin 2 8V) pL 1547 TAN Typical Output Voltage vs Output Current Ta = 25C Ci =0.4pF Cour = 6.8uF \ VIN= 27V [vn = 8V Vin = 3.8V OUTPUT VOLTAGE (V) on oS 4.9 48 0 20 40 60 80 OUTPUT CURRENT (mA) 1517 TAIZ LI WYLIC 1517-5 ABSOLUTE MAXIMUM RATINGS (Note 1) Vin tO GND ooo. eeeeeseseeeeeeeetetenseteteeseees 0.3V to 6V Vout to GND ...... ce ceeececeseesesesteeeceseseseeetetenees 0.3V to 6V Vout Short-Circuit Duration ............eeee Indefinite Operating Temperature Range: Commercial (Note 2) 0.0... teeter 0C to 70C Storage Temperature Range ................. -65C to 150C Lead Temperature (Soldering, 10 S@C).............0 300C PACKAGE/ORDER INFORMATION ORDER PART TOP VIEW NUMBER Vin CL-yi 5 ]cim eno? LTC1517C0S5-5 Vour- 43 4(7 J] c1* $5 PACKAGE S5 PART MARKING 5-LEAD PLASTIC SOT-28 Tymax = 125C, Oya = 256C/W LTCJ Consult factory for Industrial and Military grade parts and for -3 and -3.3 version availability. ELECTRICAL CHARACTERISTICS Vin = 2.7V to 5V, C1 = 0.1 pF, Cyy = 3.3uF, Coyt = 6.8uF, Tryin tO Tax, unless otherwise noted. SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS Vin Operating Input Voltage e 27 5 V Vout Output Voltage 2.7V < Vin < 5V, lot $ 10MA e 48 5.0 5.2 V 8V < Vin < DV, lout $ 20mA e 48 5.0 5.2 V lec Input Supply Current 2.7V < Vin < 5V, lout = 9 e 6 15 pA Vout Ripple Vin = 8V, Igyt = 20mA, Coyt = 6.8 uF 75 mVp_p fosc Oscillator Frequency 800 kHz ton Vour Turn-On Time Vin = 8V 1 ms The @ denotes specifications that 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. Note 2: Commercial grade parts are designed to operate over the temperature range of 40C to 85C but are neither tested nor guaranteed beyond 0C to 70C.LIC 1517-5 TYPICAL PERFORMANCE CHARACTERISTICS Output Voltage vs Input Voltage 5.15 T lout = 10mA Court = 10uF 5.10 = lu 2 5.05 5 oO > 5 5.00 5 oO 4.95 4.90 25 3.5 4.0 5.0 INPUT VOLTAGE (V) 1517-5 GO1 No Load Input Current vs Input Voltage 9 T loyt = OMA 8 = T, 0C = = 70 7 A Ty = 26C 3 "| S 6 Ta = 0 __| z = = 5 4 2.5 3.5 4.0 5.0 INPUT VOLTAGE (V) 1517-5 G04 EFFICIENCY (%) EFFICIENCY (%) Efficiency vs Input Voltage 90 \ T loyt = 10mA Ta = 25C 80 \ 70 \ 60 NX 50 MA 40 25 30 385 40 45 50 INPUT VOLTAGE (V) 1517-5 G2 Efficiency vs Output Current 90 r Vin=3V SHDN = OV Ta = 25C 80 70 / 60 50 0.01 0.1 1 10 100 OUTPUT CURRENT (mA) 1517-5 GIS Output Ripple vs Input Voltage Vin = 3V Court = 6.8uF 250 T loyt = 10mA C1 =0.1pF 900 | Ta= 25C Sa S COUT = 3.3UF leanne = 150 ma a a ay Cour= 68uE_ oc > Court = 10ynF i ae er ae] 50 oo Court = 22uF 0 2.5 3.0 3.5 4.0 45 5.0 INPUT VOLTAGE (V) 1517-5 GIS Load Transient Response lout OmA to 10mA 10mA/DIV Vout AC COUPLED 50mvV/DIV 500us/DIV 1517-5 GOS LI WYLIC 1517-5 PIN FUNCTIONS Vin (Pin 1): Charge Pump Input Voltage. May be between 2.7V and 5V. Viy should be bypassed with a >3.3uF low ESR capacitor as close as possible to the pin for best performance. GND (Pin 2): Ground. Should be tied to a ground plane for best performance. Vout (Pin 3): Regulated Output Voltage. Voyt should be bypassed with a >3.3uF low ESR capacitor as close as possible to the pin for best performance. C1* (Pin 4): Charge Pump Flying Capacitor Positive Terminal. C1~ (Pin 5): Charge Pump Flying Capacitor Negative Terminal. SIMPLIFIED BLOCK DIAGRAM Ci O.1uF 1517 BDLIC 1517-5 APPLICATIONS INFORMATION Operation The LTC1517-5 uses a switched-capacitor charge pump to boost Vijy to a 5V+4% regulated output. The part achieves regulation by sensing the output voltage through an internal resistor divider and enabling the charge pump when the divided output droops below the comparators lower trip point (Set by Vper). When the charge pump is enabled, a 2-phase nonoverlapping clock controls the internal charge pump switches. Flying capacitor C1 is charged to Vx on phase one ofthe clock. On phase two of the clock, C1 is stacked in series with Vy and connected to Vour through an internal switch. This sequence of charging and discharging the flying capacitor occurs at a free running frequency of 800kHz (typ) and continues until the divided output voltage reaches the upper trip point of the comparator. Once the output is back in regulation, the charge pump is disabled. This method of bursting the charge pump on and off enables the LTC1517-5 to achieve high efficiency at extremely low output loads. Capacitor Selection For best performance, it is recommended that low ESR capacitors be used for both Cjy and Coy to reduce noise and ripple. The Cjy and Coyz capacitors should be either ceramic or tantalum and should be 3.3uF or greater. Ceramic capacitors will provide the smallest size and lowest ESR for a given capacitance. If the input source impedance is very low (< 0.5), Cj may not be needed. Ceramic capacitors are recommended for the flying ca- pacitor C1 with values of 0.1pF or 0.22uF. Smaller value flying capacitors may be used in low Igyt applications. Output Ripple Normal LTC1517-5 operation produces voltage ripple on the Voyt pin. Output voltage ripple is required for the part to regulate. Low frequency ripple exists due to the hyster- esis inthe sense comparator and propagation delays in the charge pump enable/disable circuits. High frequency ripple is also present mainly from the ESR (equivalent series resistance) in the output capacitor. Typical output ripple with Vy =3V under maximum load is 100mV peak-to-peak with alow ESR (<0.5Q) 3.3uF output capacitor (minimum recommended Coyr). For applications requiring Vix to exceed 3.3V or for applications requiring < 100mV of peak-to-peak ripple, a 6.8uF to 10uF Coyt capacitor is recommended. Slight further decreases in output ripple can be achieved by using Coyz capacitors larger than 10uF. Short-Circuit/Thermal Protection During short-circuit conditions, the LTC1517-5 will draw between 50mA and 200mA from Vjy, causing a rise in junction temperature. On-chip thermal shutdown circuitry disables the charge pump once the junction temperature exceeds approximately 160C. The charge pump is reenabled once the junction temperature drops to approxi- mately 145C. The LTC1517-5 will cycle in and out of thermal shutdown indefinitely without latchup or damage until the Voyr short is removed. LI WYLIC 1517-5 TYPICAL APPLICATIONS Low Noise Boosted 5V Supply O.1uF sOmV/DIV AC COUPLED Vin 3.3V TO 5V Vout 2mViDIV > > AC COUPLED a Vout = 5V louT = 1MA (Vy = 3.3V) lout = 10mA (Viy 2 3.6V) TF TF r Tariana VRIPPLE < 2Vp.p Vn= 33 s0ys/DIV 5175 TAD lout =1mA Generating 5V and a Negative Supply 0.1 uF Vout = 5V +4% lout = 10mA (2.7V < Vin < 5V) lout = 20mA (3V < Vin < 5V) VIN . 2.7V TO 5V -Voyt =-1.4V TO -3.5V tsi7tas lgut = OMA to 5mA *CENTRAL SEMICONDUCTOR CMPSH-35 DUAL SCHOTTKY **OPTIONAL CIRCUITRY FOR MAINTAINING Voyt WITH LOW Vout LOADS Q1, Q2: 2N3904LIC 1517-5 PACKAGE DESCRIPTION Dimensions in inches (millimeters) unless otherwise noted. $5 Package 5-Lead Plastic SOT-23 (LTC DWG # 05-08-1633) 2.80 3.00 (0.110 0.178) (NOTE 3) A i A 190 ( /* (0.037) 2.60 3.00 (0.074) REF (0.102 0.118) REF 1.50-1.75 (0.059 0.069) 0.00 - 0.15 0.90 1.45 , ~ (0.00 0.006) { (0.035 0.057) ! iy CLI oI LI 7 J (0.004 - 0.024) 0.09 - 0.20 0.90 1.30 REF (0.004 0.008) (0.014 - 0.020) (0.035 - 0.051) (NOTE 2) FIVE PLACES (NOTE 2) $5 SOT-23 1797 NOTE: 1. DIMENSIONS ARE IN MILLIMETERS 2. DIMENSIONS ARE INCLUSIVE OF PLATING 8. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR 4. MOLD FLASH SHALL NOT EXCEED 0.254mm 5. PACKAGE ElAJ REFERENCE IS SC-74A (EIAJ) Information furnished by Linear Technology Corporation is believed to be accurate and reliable. f y LINEAR However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen- TECHNOLOGY tation that the interconnection ofits circuits as described herein will not infringe on existing patent rights.LIC 1517-5 TYPICAL APPLICATION 3.3V to 1.9V, 6A Power Supply Vin cl 3.3V Y5V CERAMIC 3.3pF C6 TO C9* 330uF C3 63V C10 0.22uF = x4 O4pF + C2 Y5V CERAMIC Qi 10uF Q2 LTC1430CS Gi G2 PVcct PVcce PGND Vec GND IFB SENSE Imax FB FREQSET SENSEt COMP ON \ OFF SHDN SS C12 0.1uF *AVX TPS TANTALUM 814410 814410 C11 rT 1 2.4uH, 8A SUMIDA CDRH127-2R4 Vout 1.9V 6A C17 TO C21 * 330uF 6.3V x5 D2 MBRS120 1517 TAN3 RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LTC1514-X Step-Up/Step-Down Switched-Capacitor DC/DC Converter with 3.3V or 5V Output Up to 50mA Low Battery Comparator LTC1515 Series Step-Up/Step-Down Switched-Capacitor DC/DC Converter with Reset Fixed or Adjustable Output Up to 50mA LTC1516 Micropower Regulated 5V Charge Pump DC/DC Converter 20mA for Viy = 2V, 50mA for Viy = 8V LTC1522 Micropower Regulated 5V Charge Pump DC/DC Converter Same as LTC1517-5 with Shutdown, Available in MSOP Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 FAX: (408) 434-0507 TELEX: 499-3977 www.linear-tech.com 15175f LT/TP 0298 4K PRINTED IN USA LY Withe LINEAR TECHNOLOGY CORPORATION 1997