Texas Instruments LM5165 | Demoboard LM5165EVM-HD-P50A

Description

The LM5165 high density EVM is designed to convert a widely-ranging input voltage supply (3 V to 65 V)to produce a tightly regulated output voltage of 5 V at currents up to 25 mA. Even though the LM5165 isavailable with fixed output versions (3.3V and 5 V), the adjustable version of the LM5165 is used here foradded flexibility in setting the output voltage. Also, the peak inductor current is limited to one of four predefinedlevels to optimize inductor size and maximize efficiency. The EVM's maximum output current isconfigured by default to 25 mA but can be changed to 50mA, 75mA, 100 mA (in PFM mode) or 150 mA(in COT mode) by suitable component selection (see Section 7).ENABLE and PGOOD connections are provided to facilitate upstream and downstream sequencing of theLM5165-based converter. The output voltage is user-adjustable by modification of the feedback resistorsas appropriate. The power train passive components selected in this design, including filter inductor andceramic input and output capacitors, are available with AEC-Q200 qualification for automotiveapplications.

Features

Tightly-regulated output voltage of 5 V, adjustable from 1.23 V to VIN

• Wide input voltage operating range of 3 V to 65 V
• Ultra-high power conversion efficiency over a wide load current range– >90% at an output voltage of 5 V and load current above 1 mA (input voltage 12 V)
• No-load supply current of 12 μA at VIN = 24 V
• Integrated high-side and low-side power MOSFETs– 2-Ω PMOS buck switch supports 100% duty cycle for low dropout voltage– 1-Ω NMOS synchronous rectifier eliminates external Schottky diode
• Pulse frequency modulation (PFM) control architecture supports all-ceramic output capacitor design– Low component count– Natural duty cycle extension to 100% for low dropout applications
• Peak inductor current level set to 60 mA by open-circuit or 100-kΩ external resistor from ILIM to GND
• Monotonic pre-bias output voltage startup
• User-adjustable soft-start ramp time set to 6 ms by 47-nF capacitor at the SS pin– Option for internal 0.9-ms soft-start time by leaving SS open circuit– Option for no soft-start for fast startup capability using 100-kΩ external resistor connected from SSto GND
• ENABLE and PGOOD terminals with 10-MΩ and 10-kΩ pull-ups to VIN and VOUT, respectively
• Resistor-programmable input UVLO with customizable hysteresis for applications with wide turn-on /turn-off voltage difference– Input UVLO internally set to turn on and off at 2.75 V and 2.45 V, respectively
• Input circuit shunt RC damping accommodates high-Q inductive supply lines
• Fully assembled, tested and proven PCB layout with 15-mm x 12-mm total footprint

Typical applications

• Building automation and HVAC
• High voltage LDO replacement
• Process control
• General-purpose bias supplies
• Automotive and battery powered equipment
• 4–20 mA current-loop powered sensors

More information

• Datasheet
• IC product information