600mA Step-down Converter
Description
The KTB851 is a high efficiency step down converter, using constant frequency PWM current mode control. It uses 1.6MHz high switching frequency which allows the use of small external components. The 2.7V to 5.5V input operating range is ideal for Li-Ion/Polymer powered devices and systems running from regulated 3.3V or 5V voltage rails. 100% duty cycle operation provides the greatest design flexibility for achieving the lowest dropout.
Low output voltage down to 0.6V can be achieved due to the KTB851’s low internal voltage reference.
The KTB851 is designed to maintain high efficiency throughout the operating range, which is critical for portable applications. In addition, the KTB851 has an option for output auto discharge feature. This enables the device to quickly discharge the output when the device is disabled.
The KTB851 is available in RoHS and Green compliant, small 5-pin TSOT23, and 6-pin UDFN 1.6 x 1.6 x 0.55mm packages.
Features
- Vin Range: 2.7V to 5.5V
- Maximum Output Current 600mA
- High Efficiency Up to 98%
- Low Quiescent Current
- High Switching Frequency: 1.6MHz
- Low Dropout in 100% Duty Cycle
- Shutdown Current < 1µA
- No Schottky Diode Required
- Output Auto Discharge when Disabled (Option)
- Integrated Soft-Start : 170µs
- Adjustable Output Voltage Down to 0.6V
- Short Circuit Protection
- Over-Temperature Protection
- Pb-Free Packages:
- KTB851 : UDFN-6, 1.6×1.6×0.55mm
- KTB851A/B : TSOT23-5
- RoHS and Green Compliant
- -40°C to +85°C Temperature Range
Applications
- Mobile Phones
- Portable Instruments
- Digital Still Cameras
- Microprocessor Power
- MP3 Players
Packaging Information
| Package | Dimensions | Bumps | Package Code |
| UDFN1.6×1.6-6 | 1.60mm x 1.60mm x 0.55mm | 6 | VD |
| TSOT23-5 | 2.80mm x 2.90mm x 0.80mm | 5 | HC |
Parameters
| Vin(Min) | Vin(Max) | IMAX Current | IQ | Interface | Output Auto-Discharge | Package |
| 2.7V | 5.5V | 600mA | 44µA | EN | Yes | UDFN1.6×1.6-6 TSOT23-5 |
Technical Documentation
| Description | Documents | Type |
|---|---|---|
| Datasheet | KTB851-04d | |
| Package Outline Drawing | TSOT23-5 HC POD | |
| Package Outline Drawing | UDFN16x16-6 VD POD |
Purchase
| Purchase Options |
|---|
| Buy from Digi-Key |
