MAX17681 Datasheet, PDF (1/18 Pages) Maxim Integrated Products – Iso-Buck DC-DC Converter

MAX17681
4.5V to 42V Input, High-Efficiency,
Iso-Buck DC-DC Converter
General Description
The MAX17681 is a high-voltage, high-efficiency, iso-
buck DC-DC converter designed to provide isolated
power up to 3W. The device operates over a wide 4.5V
to 42V input and uses primary-side feedback to regulate
the output voltage.
The MAX17681 uses peak-current-mode control. The
low-resistance, on-chip MOSFETs ensure high efficiency
at full load while simplifying the PCB layout.
The device is available in a compact 10-pin (3mm x 2mm)
TDFN package. Simulation models are available.
Applications
●● Isolated Fieldbus Interfaces
●● PLC I/O Modules
●● Smart Meters
●● Isolated Power Supplies in Medical Equipment
●● Floating Power Supply Generation
Ordering Information appears at end of data sheet.
Application Circuit
Features and Benefits
●● Reduces External Components and Total Cost
• No Opto-Coupler
• Synchronous Primary Operation
• All-Ceramic Capacitors, Compact Layout
●● Reduces Number of DC-DC Regulators to Stock
• Wide 4.5V to 42V Input
• 0.9V to 0.96 x V_IN Primary Output Voltage
• Delivers Up to 3W Output Power
●● Reduces Power Dissipation
• Peak Efficiency > 90%
• 0.9μA (typ) Shutdown Current
●● Operates Reliably in Adverse Industrial Environments
• Peak and Sink Current-Limit Protection
• ±1.7% Feedback Accuracy
• Programmable EN/UVLO Threshold
• Adjustable Soft-Start
• Overtemperature Protection
• -40°C to +125°C Operation
VIN
17V TO 32V
C1
1µF
VIN
EN/UVLO
LX
PGND
VCC
C3
GND
1µF
MAX17681
SS
C4
FB
33nF
C6
680pF
COMP
R3
4.75kΩ
C5
33nF
RESET
T1
D1
1:2.4
NPRI
NSEC
VOUT
24V, 100mA
C7
2.2µF
R4
49.9Ω
Z1
R1
105kΩ
R2
10kΩ
C2
10uF
C8
1nF
19-7053; Rev 0; 9/14