MT3688 is a high performance Primary Side Regulation (PSR) controller with high precision CV/CC control ideal for charger applications. In CV mode, MT3688 adopts Multi Mode Control which uses the hybrid of AM (Amplitude Modulation) mode and FM (Frequency Modulation) mode to improve system efficiency and reliability. In CC mode, the IC uses PFM control with line and load CC compensation. The IC can achieve audio noise free operation and optimized dynamic response. MT3688 The built-in Cable Drop Compensation (CDC) function can provide excellent CV performance. MT3688 integrates functions and protections of Under Voltage Lockout (UVLO), VCC over Voltage Protection (VCC OVP), Cycle-by-cycle Current Limiting (OCP), Short Load Protection (SLP), Gate Clamping, and VCC Clamping.
MT3688A: 12W; MT3688B: 15W; MT3688C: 18W; MT3688D: 24W;
Short Load Protection (SLP)
In MT3688, the output is sampled on FB pin and then compared with a threshold of UVP(0.7V typically)after an internal blanking time(30ms typical).
In MT3688. when sensed FB voltage is below 0.7V, the IC will enter into Short Load Protection (SLP) mode, in which the IC will enter into auto recovery protection mode.
VCC Over Voltage Protection (OVP) and Zener Clamp
When VCC voltage is higher than 30V (typical),the IC will stop switching. This will cause VCC fall down to be lower than VCC OFF (typical 9V)and then the system will restart up again. An internal 34.5V(typical)zener clamp is integrated to prevent the lC from damage.
On Chip Thermal Shutdown (OTP)
When the IC temperature is over 165℃. the IC shuts down. Only when the IC temperature drops to 135℃, IC will restart.
Pin Floating Protection
In MT3688, if pin floating situation occurs,the IC is designed to have no damage to system.
Soft Totem-Pole Gate Driver
MT3688 has a soft totem-pole gate driver with optimized EMl performance.