This highly integrated PWM controller provides several features to enhance the performance of low-power flyback converters. The patented topology of SGP100 enables simplified circuit design for battery charger applications. The result is a low-cost, smaller and lighter charger than a conventional design or a linear transformer.

To minimize the standby power consumption, the proprietary green-mode function provides off-time modulation to linearly decrease PWM frequency under light-load conditions. This green-mode function allows the power supply to meet power conservation requirements. The start-up current is only 10µA, which allows large start-up resistance for further power saving.

A charger can be implemented with few external components and minimal cost. A typical output CV/CC characteristic envelope is provided.

• Constant-voltage (CV) and constant-current (CC) control without secondary-feedback circuitry
• Green-mode function: PWM frequency linearly decreasing
• Fixed PWM frequency at 42kHz with frequency hopping to solve EMI problems
• Low start-up current: 10µA (typical)
• Low operating current: 6.5mA (typical)
• Peak-current-mode control in CV mode
• Cycle-by-cycle current limiting
• V_DD over-voltage protection with latch (OVP)
• V_DD under-voltage lockout (UVLO)
• Gate output maximum voltage clamped at 18V
• Fixed over-temperature protection with latch

• Battery chargers for cellular phones, cordless phones, PDAs, digital cameras, and power tools
• Replacements for linear transformers and RCC SMPS