Datasheet LT1680 (Analog Devices)
| Manufacturer | Analog Devices |
| Description | High Power DC/DC Step-Up Controller |
| Pages / Page | 16 / 1 — FEATURES. DESCRIPTIO. High Voltage: Operation Up to 60V. High Current: … |
| File Format / Size | PDF / 228 Kb |
| Document Language | English |
FEATURES. DESCRIPTIO. High Voltage: Operation Up to 60V. High Current: N-Channel Drive Handles Up to. 10,000pF Gate Capacitance
Model Line for this Datasheet
Text Version of Document
LT1680 High Power DC/DC Step-Up Controller
U FEATURES DESCRIPTIO
■
High Voltage: Operation Up to 60V
The LT®1680 is a high power, current mode switching ■
High Current: N-Channel Drive Handles Up to
power supply controller optimized for boost topologies.
10,000pF Gate Capacitance
The IC drives an N-channel MOSFET switch for DC/DC ■ Programmable Average Current Limiting converter applications up to 60V input. A high current gate ■ 5V Reference Output with 10mA External drive output handles up to 10,000pF gate capacitance, Loading Capability enabling the construction of high power DC/DC convert- ■ Fixed Frequency Current Mode Operation ers. Current sense common mode range up to 60V allows ■ Oscillator Synchronizable Up to 200kHz current sensing to be referenced to the input supply, ■ Undervoltage Lockout with Hysteresis eliminating the need for sense blanking circuits. ■ Programmable Start Inhibit for Power Supply The LT1680 incorporates programmable average current Sequencing and Protection limiting allowing accurate limiting of DC current in the ■ User Adjustable Slope Compensation magnetics, independent of ripple current . User adjustable slope compensation provides stable operation at duty
U
cycles up to 90%.
APPLICATIO S
The LT1680 operating frequency is programmable and ■ High Power Single Board Systems can be synchronized up to 200kHz. Minimum off-time ■ Distributed Power Converters operation provides switch protection. The IC also incorpo- ■ Industrial Control Systems rates a soft start feature that is gated by both shutdown ■ Lead-Acid Battery Back-Up Systems and undervoltage lockout conditions. ■ Automotive and Heavy Equipment , LTC and LT are registered trademarks of Linear Technology Corporation.
U TYPICAL APPLICATIO 12V to 48V, 250W Boost Converter
12VIN 10V TO 15V R C2 SENSE 24A (DC) 0.005Ω
Efficiency vs Output Power
1µF 100 + CIN VOUT = 48V RCT LT1680 680µF L1 CCT 15k 25V 1 16 25µH 1nF 95 SL/ADJ 5V ×4 REF 2 15 C + T SYNC C12 C3 220pF 3 14 I 1µF 90 AVG 12VIN C4 0.22µF 4 13 M1 SS GATE IRFZ44 5 12 ×3 C V 85 VC 4.7nF C PGND 6 11 R9 EFFICIENCY (%) R SGND RUN/SHDN 100k VC 4.7k 7 10 MBR0520 V 80 FB SENSE – 8 9 C11 1nF VREF SENSE + D1 R7 R6 MBR20100CT C6 0.1µF 2k 75k × 75 2 VOUT 0 50 100 150 200 250 48V COUT 5.2A + OUTPUT POWER (W) 680µF L1: Kool Mµ®, 18T #14 ON 77314-A7 1680 TA02 63V Kool Mµ IS A REGISTERED TRADEMARK OF MAGNETICS, INC. ×3 1680 TA01 1
U FEATURES DESCRIPTIO
■
High Voltage: Operation Up to 60V
The LT®1680 is a high power, current mode switching ■
High Current: N-Channel Drive Handles Up to
power supply controller optimized for boost topologies.
10,000pF Gate Capacitance
The IC drives an N-channel MOSFET switch for DC/DC ■ Programmable Average Current Limiting converter applications up to 60V input. A high current gate ■ 5V Reference Output with 10mA External drive output handles up to 10,000pF gate capacitance, Loading Capability enabling the construction of high power DC/DC convert- ■ Fixed Frequency Current Mode Operation ers. Current sense common mode range up to 60V allows ■ Oscillator Synchronizable Up to 200kHz current sensing to be referenced to the input supply, ■ Undervoltage Lockout with Hysteresis eliminating the need for sense blanking circuits. ■ Programmable Start Inhibit for Power Supply The LT1680 incorporates programmable average current Sequencing and Protection limiting allowing accurate limiting of DC current in the ■ User Adjustable Slope Compensation magnetics, independent of ripple current . User adjustable slope compensation provides stable operation at duty
U
cycles up to 90%.
APPLICATIO S
The LT1680 operating frequency is programmable and ■ High Power Single Board Systems can be synchronized up to 200kHz. Minimum off-time ■ Distributed Power Converters operation provides switch protection. The IC also incorpo- ■ Industrial Control Systems rates a soft start feature that is gated by both shutdown ■ Lead-Acid Battery Back-Up Systems and undervoltage lockout conditions. ■ Automotive and Heavy Equipment , LTC and LT are registered trademarks of Linear Technology Corporation.
U TYPICAL APPLICATIO 12V to 48V, 250W Boost Converter
12VIN 10V TO 15V R C2 SENSE 24A (DC) 0.005Ω
Efficiency vs Output Power
1µF 100 + CIN VOUT = 48V RCT LT1680 680µF L1 CCT 15k 25V 1 16 25µH 1nF 95 SL/ADJ 5V ×4 REF 2 15 C + T SYNC C12 C3 220pF 3 14 I 1µF 90 AVG 12VIN C4 0.22µF 4 13 M1 SS GATE IRFZ44 5 12 ×3 C V 85 VC 4.7nF C PGND 6 11 R9 EFFICIENCY (%) R SGND RUN/SHDN 100k VC 4.7k 7 10 MBR0520 V 80 FB SENSE – 8 9 C11 1nF VREF SENSE + D1 R7 R6 MBR20100CT C6 0.1µF 2k 75k × 75 2 VOUT 0 50 100 150 200 250 48V COUT 5.2A + OUTPUT POWER (W) 680µF L1: Kool Mµ®, 18T #14 ON 77314-A7 1680 TA02 63V Kool Mµ IS A REGISTERED TRADEMARK OF MAGNETICS, INC. ×3 1680 TA01 1
