Datasheet LTC1702A (Analog Devices)

LTC1702A Dual 550kHz Synchronous 2-Phase Switching Regulator Controller
U FEATURES DESCRIPTIO
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Pin Compatible with the LTC1702 with Improved
The LTC®1702A is a dual switching regulator controller
Current Limit Control
optimized for high efficiency with low input voltages. It ■
Two Sides Run Out-of-Phase to Minimize C
includes two complete, on-chip, independent switching regu-
IN
■
No External Current Sense Resistors
lator controllers each designed to drive a pair of external N- ■
Excellent Output Regulation: 1% Total Output
channel MOSFETs in a voltage mode feedback, synchronous
Accuracy
buck configuration. The LTC1702A uses a constant-fre- ■ Two Independent Controllers in One Package quency, true PWM design switching at 550kHz, minimizing ■ All N-Channel External MOSFET Architecture external component size and cost and maximizing load ■ 550kHz Switching Frequency Minimizes External transient performance. The synchronous buck architecture Component Size automatically shifts to discontinuous and then to Burst ■ 1A to 25A Output Current per Channel Mode® operation as the output load decreases, ensuring ■ High Efficiency over Wide Load Current Range maximum efficiency over a wide range of load currents. ■ Less Than 100µA Shutdown Current The LTC1702A features an onboard reference trimmed to ■ Small 24-Pin Narrow SSOP Package 0.5% and can provide better than 1% regulation at the
U
converter outputs. Open-drain logic outputs indicate whether
APPLICATIO S
either output has risen to within 5% of the final output voltage ■ Microprocessor, DSP Core and I/O Supplies and an optional latching FAULT mode protects the load if the ■ Multiple Logic Supply Generator output rises 15% above the intended voltage. Each channel ■ Distributed Power Applications can be enabled independently; with both channels disabled, ■ High Efficiency Power Conversion the LTC1702A shuts down and supply current drops below 100 , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. µA. Burst Mode is a registered trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents including 6144194.
U TYPICAL APPLICATIO Dual Output High Power 3.3V/2.5V Logic Supply
VIN = 5V ±10% COUT1, COUT2: PANASONIC EEFUE0G181R + C C IN: KEMET TS10X337M010AS 10Ω 10 D1 µF IN D2 D1, D2: MOTOROLA MBR0520LT1 330µF D3, D4: MOTOROLA MBRS320T3 ×3 1µF L1, L2: SUMIDA CEP125-1R0 1 24 11.8k Q1 TO Q8: FAIRCHILD FDS6670A 1µF PVCC IMAX2 1µF 1µF 2 23 10µF BOOST1 BOOST2 3 22 Q1 Q2 BG1 BG2 Q5 Q6 4 21 L1 L2 TG1 TG2 V 1µH 1µH OUT1 5 20 VOUT2 2.5V SW1 SW2 3.3V AT 15A 11.8k 6 19 AT 15A D3 Q3 Q4 + D4 I Q7 Q8 C MAX1 PGND OUT1 1µF LTC1702A 180µF 7 18 1.2k 1.6k PGOOD1 PGOOD2 ×4 8 17 + 10k C 820pF FCB FAULT 15.8k OUT2 1µF 1% 180µF 9 16 680pF 1% RUN/SS RUN/SS2 ×4 1µF 10 15 1µF COMP1 COMP2 4.75k 4.99k 47k 11 14 68k 1% 1% SGND FB2 V V IN IN 12 13 680pF 27pF FB1 V 27pF 3300pF CC 10k 10k PWRGD1 PWRGD2 FAULT 1702 TA01 1702afa 1