The controller utilizes a constant on-time control scheme which eliminates the need for external compensation components, allowing the power supply designer to minimize necessary board space and reduce costs.
This design regulates the output at the LM1770’s reference voltage. There are no feedback resistors necessary for this design as the output voltage is connected directly to the feedback pin. A 6.8µH inductor and a 150µF POSCAP output capacitor are used to create enough ripple at the output to ensure stability. No feedforward capacitor is necessary.
| Manufacturer | Texas Instruments |
|---|---|
| Category | AC/DC and DC/DC Conversion |
| Sub-Category | DC/DC SMPS - Single Output |
| Eval Board |
ABC
|
| Topology |
Step Down
|
| Outputs and Type |
1 Non-Isolated
|
| Output Voltage: Factory Set |
0.8 V
|
| Current Out |
2 A
|
| Voltage In |
5 V
|
| Efficiency @ Conditions |
>83%, 5 Vin, 0.8 V @ 0.2 ~ 2 A
|
| Voltage Out Range | |
| Features |
Short Circuit Protection
Soft Start |
| Switching Frequency |
242 kHz
|
| Standby Current [Typical] | |
| Quiescent Current [Typical] |
400 µA
|
| Component Count + Extras |
7 + 0
|
| Internal Switch |
No
|
| Design Author |
Texas Instruments
|
| Application / Target Market |
Computers
DVD Players Point of Load (PoL) Portable Devices Set-Top Boxes Telecom USB Powered Devices White Goods |
| Main I.C. Base Part |
LM1770T
|
| Standby Current [Maximum] | |
| Quiescent Current [Maximum] |
600 µA
|
| Date Created By Author | |
| Date Added To Library | 2011-03 |
