LTC1266 LTC1266-3.3/LTC1266-5 Synchronous Regulator Controller for N- or P-Channel MOSFETs FEATURES DESCRIPTIO n Ultrahigh Efficiency: Over 95% Possible The LTC 1266 series is a family of synchronous switching TM n Drives N-Channel MOSFET for High Current or regulator controllers featuring automatic Burst Mode P-Channel MOSFET for Low Dropout operation to maintain high efficiencies at low output n Pin Selectable Burst Mode Operation currents. These devices drive external power MOSFETs at n 1% Output Accuracy (LTC1266A) switching frequencies up to 400kHz using a constant off- n Pin Selectable Phase of Topside Driver for Boost time current mode architecture providing constant ripple or Step-Down Operation current in the inductor. They can drive either an N-channel n Wide V Range: 3.5V to 20V or a P-channel topside MOSFET. IN n On-Chip Low-Battery Detector The operating current level is user-programmable via an n High Efficiency Maintained Over Large Current Range external current sense resistor. Wide input supply range n Low 170m A Standby Current at Light Loads allows operation from 3.5V to 18V (20V maximum). n Current Mode Operation for Excellent Line and Load Constant off-time architecture provides low dropout regu- Transient Response lation limited only by the R of the topside MOSFET DS(ON) n Logic Controlled Micropower Shutdown: I < 40m A Q (when using the P-channel) and the resistance of the n Short-Circuit Protection inductor and current sense resistor. n Synchronous Switching with Nonoverlaping Gate Drives The LTC1266 series combines synchronous switching for n Available in 16-Pin Narrow SO Package maximum efficiency at high currents with an automatic U low current operating mode, called Burst Mode operation, APPLICATIO S which reduces switching losses. Standby power is re- n Notebook and Palmtop Computers duced to only 1mW at V = 5V (at I = 0). Load currents IN OUT n Portable Instruments in Burst Mode operation are typically 0mA to 500mA. n Cellular Telephones , LTC and LT are registered trademarks of Linear Technology Corporation. n DC Power Distribution Systems Burst Mode is a trademark of Linear Technology Corporation. n GPS Systems TYPICAL APPLICATIO D2 MBR0530T1 LTC1266-3.3 Efficiency V IN 100 4V TO 9V + C LOW BAT OUT IN V = 5V IN 100m F C 2 B V PWR V IN IN 0.1m F 100k 95 LOW BAT IN LB LB IN OUT N-CHANNEL L* R SENSE PINV TDRIVE Si9410 5m H 0.02W V OUT LTC1266-3.3 3.3V 90 0V = NORMAL + 5A SHDN SENSE >1.5V = SHUTDOWN 1000pF I TH SENSE R C C T + C OUT 470W N-CHANNEL 85 C BINH BDRIVE D1 330m F T Si9410 MBRS130LT3 C 180pF 2 C SGND PGND 3300pF 1266 TA01 80 *TOKO 919AS-4R7M 0.01 0.1 1 5 LOAD CURRENT (A) Figure 1. High Efficiency Step-Down Converter 1266 TA02 1 EFFICIENCY (%) U ULTC1266 LTC1266-3.3/LTC1266-5 UUW ABSOLUTE AXI U RATI GS PACKAGE/ORDER I FOR ATIO (Note 1) TOP VIEW ORDER PART Input Supply Voltage (Pins 2, 5) ............... 20V to 0.3V NUMBER TDRIVE BDRIVE 1 16 Continuous Output Current (Pins 1, 16) .............. 50mA PWR V PGND 2 15 IN Sense Voltages (Pins 8, 9) ....................... 13V to 0.3V LTC1266CS PINV LB 3 14 OUT SHDN Voltage (Pin 11) ............................. 12V to 0.3V LTC1266CS-3.3 BINH LB 4 13 IN PINV, BINH, LB (Pins 3, 4, 13)................20V to 0.3V IN LTC1266CS-5 V SGND 5 12 IN LB Output Current ........................................... 12mA OUT LTC1266ACS C SHDN 6 11 T Operating Ambient Temperature Range ...... 0 C to 70 C LTC1266IS I V (NC*) 7 10 TH FB Industrial Temperature Range ................ 40 C to 85 C + LTC1266IS-3.3 SENSE SENSE 8 9 Extended Commercial LTC1266IS-5 S PACKAGE Temperature Range ........................... 40 C to 85 C 16-LEAD PLASTIC SO LTC1266AIS Junction Temperature (Note 2)............................ 125 C *FIXED OUTPUT VERSIONS T = 125 C, q = 110 C/ W Storage Temperature Range ................ 65 C to 150 C JMAX JA Lead Temperature (Soldering, 10 sec)................. 300 C Consult factory for Industrial and Military grade parts. ELECTRICAL CHARACTERISTICS The l denotes specifications which apply over the full operating temperature range, otherwise specifications are at T = 25 C. V = 10V, V = V = 0V unless otherwise noted. A IN SHDN BINH SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS V Feedback Voltage V = 9V, I = 700mA, V = V = 14V, FB IN LOAD PINV PWR Topside Switch = N-Ch LTC1266ACS l 1.252 1.265 1.278 V LTC1266CS l 1.210 1.265 1.290 V I Feedback Current (LTC1266 Only) l 0.2 1 m A FB V Regulated Output Voltage V = 9V, I = 700mA, V = V = 14V, OUT IN LOAD PINV PWR Topside Switch = N-Ch LTC1266CS-3.3 l 3.23 3.33 3.43 V LTC1266CS-5 l 4.90 5.05 5.20 V Output Ripple (Burst Mode Operation) I = 150mA 50 mV LOAD P-P D V Output Voltage Line Regulation I = 50mA OUT LOAD V = 0V, Topside Switch = P-Ch, V = 7V to 12V 40 0 40 mV PINV IN V = V , Topside Switch = N-Ch, V = 7V to 12V 40 0 40 mV PINV PWR IN Output Voltage Load Regulation 5mA < I < 2A, R = 0.05W LOAD SENSE LTC1266-3.3 Burst Mode Operation Enabled, V = 0V l 40 65 mV BINH LTC1266-3.3 Burst Mode Operation Inhibited, V = 2V l 15 25 mV BINH LTC1266-5 Burst Mode Operation Enabled, V = 0V l 60 100 mV BINH LTC1266-5 Burst Mode Operation Inhibited, V = 2V l 25 40 mV BINH I V Pin DC Supply Current (Note 3) Q1 IN Normal Mode 3.5V < V < 18V 2.1 3.0 mA IN Sleep Mode 3.5V < V < 18V 170 250 m A IN Shutdown V = 2.1V, 3.5V < V < 18V 25 50 m A SHDN IN I PWR V DC Supply Current (Note 3) Q2 IN Normal Mode 3.5V < PWR V < 18V 20 40 m A IN Sleep Mode 3.5V < PWR V < 18V 1 5 m A IN Shutdown V = 2.1V, 3.5V < PWR V < 18V 1 5 m A SHDN IN 2 U WWW