Datasheet LT3988 (Analog Devices)
| Manufacturer | Analog Devices |
| Description | Dual 60V Monolithic 1A Step-Down Switching Regulator |
| Pages / Page | 24 / 1 — FeaTures. DescripTion. Wide Input Range:. Operation from 4.1V to 60V. … |
| File Format / Size | PDF / 287 Kb |
| Document Language | English |
FeaTures. DescripTion. Wide Input Range:. Operation from 4.1V to 60V. Overvoltage Lockout Protects Circuit Through
Model Line for this Datasheet
Text Version of Document
LT3988 Dual 60V Monolithic 1A Step-Down Switching Regulator
FeaTures DescripTion
n
Wide Input Range:
The LT®3988 is a dual, current mode, step-down, DC/DC
Operation from 4.1V to 60V
converter that accepts two input voltages up to 60V (80V
Overvoltage Lockout Protects Circuit Through
transient), which may be driven from separate supplies or
80V Transients
can be cascaded. High efficiency switches are included on n
Two 1A Output Switching Regulators with Internal
the die along with internal boost diodes and loop compensa-
Power Switches
tion. Both converters are capable of generating 1A outputs, n
Short Circuit Robust
are synchronized to a single oscillator programmable up n
Adjustable 250kHz to 2.5MHz Switching Frequency,
to 2.5MHz, and run with opposite phases, reducing input
Synchronizable Over the Full Range
ripple current. n
Integrated Boost Diodes
The switching frequency is set with a single resistor yield- n
Integrated Loop Compensation
ing a range of 250kHz to 2.5MHz, or a clock signal can n Anti-Phase Switching Reduces Ripple be applied to the SYNC pin. The LT3988’s high switching n Low Shutdown IQ (<2µA) frequency allows the use of small inductors and capacitors, n Uses Small Inductors and Ceramic Capacitors resulting in a very small dual output supply. The constant n Thermally Enhanced, 16-Lead MSOP Package switching frequency, combined with low impedance ce- ramic capacitors, results in low, predictable output ripple.
applicaTions
A current mode PWM architecture provides fast transient n response with cycle-by-cycle current limiting. Diode current Commercial Vehicle Battery Regulation n sense and thermal shutdown provide additional protection. Industrial Supplies n Distributed Supply Regulation The LT3988 is available in a 16-lead MSOP package with L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks an exposed pad for low thermal resistance. of Linear Technology Corporation. All other trademarks are the property of their respective owners.
Typical applicaTion
VIN
Efficiency
7V TO 60V 4.7µF 90 TRANSIENT VIN1 VIN2 V TO 80V OUT = 5V EN/UVLO TRACK/SS2 85 TRACK/SS1 1000pF 80 1000pF RT V LT3988 OUT = 3.3V SYNC 200k 75 BD BOOST1 BOOST2 70 22µH 0.22µF 0.22µF 15µH VOUT1 VOUT2 5V, 1A SW1 SW2 3.3V, 1A EFFICIENCY (%) 65 60 57.6k DA1 DA2 34k 55 FB1 FB2 VIN = 12V GND fSW = 500kHz 50 47µF 10.2k 10k 47µF 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 22pF IOUT (A) 3988 TA01 3988 TA01b 3988f 1 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Applications Package Description Typical Application Related Parts
FeaTures DescripTion
n
Wide Input Range:
The LT®3988 is a dual, current mode, step-down, DC/DC
Operation from 4.1V to 60V
converter that accepts two input voltages up to 60V (80V
Overvoltage Lockout Protects Circuit Through
transient), which may be driven from separate supplies or
80V Transients
can be cascaded. High efficiency switches are included on n
Two 1A Output Switching Regulators with Internal
the die along with internal boost diodes and loop compensa-
Power Switches
tion. Both converters are capable of generating 1A outputs, n
Short Circuit Robust
are synchronized to a single oscillator programmable up n
Adjustable 250kHz to 2.5MHz Switching Frequency,
to 2.5MHz, and run with opposite phases, reducing input
Synchronizable Over the Full Range
ripple current. n
Integrated Boost Diodes
The switching frequency is set with a single resistor yield- n
Integrated Loop Compensation
ing a range of 250kHz to 2.5MHz, or a clock signal can n Anti-Phase Switching Reduces Ripple be applied to the SYNC pin. The LT3988’s high switching n Low Shutdown IQ (<2µA) frequency allows the use of small inductors and capacitors, n Uses Small Inductors and Ceramic Capacitors resulting in a very small dual output supply. The constant n Thermally Enhanced, 16-Lead MSOP Package switching frequency, combined with low impedance ce- ramic capacitors, results in low, predictable output ripple.
applicaTions
A current mode PWM architecture provides fast transient n response with cycle-by-cycle current limiting. Diode current Commercial Vehicle Battery Regulation n sense and thermal shutdown provide additional protection. Industrial Supplies n Distributed Supply Regulation The LT3988 is available in a 16-lead MSOP package with L, LT, LTC, LTM, Linear Technology, the Linear logo and Burst Mode are registered trademarks an exposed pad for low thermal resistance. of Linear Technology Corporation. All other trademarks are the property of their respective owners.
Typical applicaTion
VIN
Efficiency
7V TO 60V 4.7µF 90 TRANSIENT VIN1 VIN2 V TO 80V OUT = 5V EN/UVLO TRACK/SS2 85 TRACK/SS1 1000pF 80 1000pF RT V LT3988 OUT = 3.3V SYNC 200k 75 BD BOOST1 BOOST2 70 22µH 0.22µF 0.22µF 15µH VOUT1 VOUT2 5V, 1A SW1 SW2 3.3V, 1A EFFICIENCY (%) 65 60 57.6k DA1 DA2 34k 55 FB1 FB2 VIN = 12V GND fSW = 500kHz 50 47µF 10.2k 10k 47µF 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 22pF IOUT (A) 3988 TA01 3988 TA01b 3988f 1 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Applications Package Description Typical Application Related Parts
