This Flybuck reference design uses the LM5017 buck regulator to generate four isolated outputs: ±15V@50mA and ±5V@100mA. The regulation is done on the primary side, and thus no opto-coupler is needed. The overall load/line regulation for each output is within +/-5%. The input voltage range is from 17V to 32V. It's suitable for applications requiring multiple positive and negative bias voltage rails.
The LM5017 is a 100 V, 600 mA synchronous step- down regulator with integrated high side and low side MOSFETs. The constant-on-time (COT) control scheme employed in the LM5017 requires no loop compensation, provides excellent transient response, and enables very low step-down ratios. The on-time varies inversely with the input voltage resulting in nearly constant frequency over the input voltage range. A high voltage startup regulator provides bias power for internal operation of the IC and for integrated gate drivers.
Manufacturer | Texas Instruments |
---|---|
Category | AC/DC and DC/DC Conversion |
Sub-Category | DC/DC SMPS - Multi Output |
Eval Board |
Board not Stocked
|
Topology |
Step Down
|
Outputs and Type |
4 Isolated
|
Voltage Out: Highest Current First |
±5V, ±15V
|
Current Out |
100mA, 50mA
|
Voltage In |
17 ~ 32 V
|
Efficiency @ Conditions |
>75%, 24V in, 80 ~ 100% load
>75%, 17V in, 75 ~ 100% load >70%, 32V in, 65 ~ 100% load |
Voltage Out Range |
- Fixed
|
Features |
Current Limit (Adj. or Fixed)
Shutdown, Enable, Standby Thermal Protection Under Voltage Protection, Brown-Out |
Switching Frequency |
260 kHz
|
Standby Current [Typical] |
50 µA
|
Quiescent Current [Typical] |
1.75 mA
|
Component Count + Extras |
30 + 13
|
Internal Switch |
Yes
|
Design Author |
Texas Instruments
|
Application / Target Market |
Automotive
Power: Auxiliary Power Supply RF: Metering Telecom |
Standby Current [Maximum] |
225 µA
|
Quiescent Current [Maximum] |
- Not Given
|
Main I.C. Base Part |
LM5017
|
Date Created By Author | 2013-08 |
Date Added To Library | 2014-12 |