MAX1774：Dual, High-Efficiency, Step-Down Converter with Backup Battery Switchover
Dual-Output Step-Down DC-DC Converter Supplies PDA/Palmtop Computers with Automatic Battery Switchover
The MAX1774 is a complete power-supply solution for PDAs and other hand-held devices. It integrates two high-efficiency step-down converters, a boost converter for backup battery regulation, and four voltage detectors in a small 32-pin QFN or 28-pin QSOP package. The MAX1774 accepts inputs from +2.7V to +28V and provides an adjustable main output from 1.25V to 5.5V atover 2A. The secondary core converter delivers an adjustable voltage from 1V to 5V and can deliver up to 1.5A. Both the main and core regulators have separate shutdown inputs. When the AC adapter power is removed, an external P-channel MOSFET switches input to the main battery. When the main battery is low, the backup step-up converter sustains the main output voltage. When the backup battery can no longer deliver the required load, the system shuts down safely to prevent damage. Four on-board voltage detectors monitor the status of the AC adapter power, main battery, and backup battery. The MAX1774 evaluation kit is available to help reduce design time.
Key Features
| MAX1774: Functional Diagram Applications/Uses
|
DataSheet
| title | Download file |
|---|---|
| MAX1774 Data Sheet | MAX1774.pdf |
Parametrics
| Part Number | Primary Topology | Monitor/Control Features | DC-DC/Power Features | Battery Charger Features | VIN (V) | VIN (V) | VOUT (V) | VOUT (V) | Max. IOUT (A) | Max. IOUT (A) | Oper. Freq. (kHz) | Package/Pins | Budgetary Price |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| min | max | min | max | See Notes | |||||||||
| MAX1774 | Step-Down | Shutdown | Current Limit Fixed Freq./PWM Soft Start Sync. Rectifier | Battery Backup | 2.7 | 28 | 1 | 5.5 | 2 | 2 | 600 | QSOP/28 | $4.03 @1k |
Design kits & evaluation modules
Related Products
- MAX1775：Dual-Output Step-Down DC-DC Converter for PDA/Palmtop Computers
Ordering Information
| Part Number | Status | Recommended Replacement | Package | Temp | RoHS |
|---|---|---|---|---|---|
| MAX1774EEI | No Longer Available | MAX1774EEI+ | QSOP,;28 pin;61.9 mm² | -40°C to +85°C | No |
| MAX1774EEI+ | Active | QSOP,;28 pin;61.9 mm² | -40°C to +85°C | Lead Free | |
| MAX1774EEI+T | Active | QSOP,;28 pin;61.9 mm² | -40°C to +85°C | Lead Free | |
| MAX1774EEI-T | No Longer Available | MAX1774EEI+T | QSOP;28 pin | -40°C to +85°C | See data sheet |
| MAX1774EMJ | No Longer Available | MAX1774EEI+ | -40°C to +85°C | See data sheet |
- MAX1774.pdf MAX1774
- DAC Makes Controller Programmable MAX5222
- Protection From Blackouts: Dirt Cheap to Fully Integrated MAX8211
- 功能框图 MAX1774
