LT3988 - Dual 60V Monolithic 1A Step-Down Switching Regulator


  • Wide Input Range:
    Operation from 4.1V to 60V
    Overvoltage Lockout Protects Circuit Through
    80V Transients
  • Two 1A Output Switching Regulators with Internal Power Switches
  • Short Circuit Robust
  • Adjustable 250kHz to 2.5MHz Switching Frequency, Synchronizable Over the Full Range
  • Integrated Boost Diodes
  • Integrated Loop Compensation
  • Anti-Phase Switching Reduces Ripple
  • Low Shutdown IQ (<2μA)
  • Uses Small Inductors and Ceramic Capacitors
  • Thermally Enhanced, 16-Lead MSOP Package

Typical Application

LT3988 Typical Application
LT3988 Typical Application


The LT®3988 is a dual, current mode, step-down, DC/DC converter that accepts two input voltages up to 60V (80V transient), which may be driven from separate supplies or can be cascaded. High efficiency switches are included on the die along with internal boost diodes and loop compensation. Both converters are capable of generating 1A outputs, are synchronized to a single oscillator programmable up to 2.5MHz, and run with opposite phases, reducing input ripple current.

The switching frequency is set with a single resistor yielding a range of 250kHz to 2.5MHz, or a clock signal can be applied to the SYNC pin. The LT3988’s high switching frequency allows the use of small inductors and capacitors, resulting in a very small dual output supply. The constant switching frequency, combined with low impedance ceramic capacitors, results in low, predictable output ripple. A current mode PWM architecture provides fast transient response with cycle-by-cycle current limiting. Diode current sense and thermal shutdown provide additional protection.

The LT3988 is available in a 16-lead MSOP package with an exposed pad for low thermal resistance.


For complete and up to date package information and drawings, please refer to our packaging page

Part Number Package Code Temp Package
LT3988EMSE#PBF MS-16E MSE E 05-08-1667 RoHS
LT3988EMSE#TRPBF MS-16E MSE E 05-08-1667 RoHS
LT3988HMSE#PBF MS-16E MSE H 05-08-1667 RoHS
LT3988HMSE#TRPBF MS-16E MSE H 05-08-1667 RoHS
LT3988IMSE#PBF MS-16E MSE I 05-08-1667 RoHS
LT3988IMSE#TRPBF MS-16E MSE I 05-08-1667 RoHS

LT3988 Package Drawing

Order Info

  • Part numbers ending in PBF are lead free. Solder plated terminal finish (SnPb) versions are non-standard and special terms and conditions and pricing applies if available. Please contact LTC marketing for information.
  • Part numbers containing TR or TRM are shipped in tape and reel or 500 unit mini tape and reel, respectively
  • Please refer to our general ordering information or the product datasheet for more details

Package Variations and Pricing

Part Number Package Temp Price
LT3988EMSE#PBF MS-16E E $5.22 $3.65 Yes
LT3988EMSE#TRPBF MS-16E E $3.71 Yes
LT3988HMSE#PBF MS-16E H $6.36 $4.45 Yes
LT3988HMSE#TRPBF MS-16E H $4.51 Yes
LT3988IMSE#PBF MS-16E I $6.00 $4.20 Yes
LT3988IMSE#TRPBF MS-16E I $4.26 Yes
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* The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Linear Technology sales office or authorized distributor.

Demo Boards

Linear Technology offers many demo boards free of charge to qualified customers. Contact your local sales office or distributor to inquire about a demo board. Certain demo boards are also available for sale via credit card on this website. Demo boards are for evaluation purposes only. It remains the customer’s responsibility to verify proper and reliable operation in the actual end application.

Part Number Description Price Documentation
DC1677A LT3988EMSE Demo Board I 7V ≤ VIN ≤60V, Vout1 = 5V @ 1A, Vout2 = 3.3V @ 1A $150.00
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Click here to view our complete list of demo boards


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