EA8951T8R

EA8951 is a frequency-adjustable synchronous buck converter with a wide input voltage range, employing fixed on-time (COT) control. Both high-side and low-side power transistors are integrated on-chip, supporting input voltages from 6V to 100V with output load current up to 1A and a switching frequency adjustable up to 1MHz. With constant ΔV_OUT and R_RON, the COT control architecture delivers near-constant switching frequency and excellent load transient response. The device operates in discontinuous conduction mode (DCM) under light-load conditions to maintain high efficiency and ultra-low quiescent current. Additional features include output voltage monitoring, peak-valley overcurrent protection, integrated on-chip VCC bias supply and bootstrap diode, precision enable and input undervoltage lockout, and auto-recovery thermal shutdown protection. The EA8951 is housed in an 8-pin ESOP8 package and operates over a temperature range of –40°C to 105°C. As an ultra-low I_Q COT synchronous buck converter, it requires no control loop compensation, reducing design complexity and external component count. To meet comprehensive system requirements, it also features a power-good open-drain indicator for power sequencing and fault reporting, internal fixed soft-start, precision programmable linear undervoltage lockout (UVLO), cycle-by-cycle overcurrent protection, and auto-recovery thermal shutdown. Output voltage regulation is achieved by comparing the feedback voltage V_FB against an internal 1.2V reference, with the output voltage set via R_FB1 and R_FB2 resistors. A dual-level EN/UVLO circuit supports different operating modes based on the EN/UVLO voltage level. Internal soft-start is implemented with a fixed 3ms duration. The on-time of the high-side power transistor and switching frequency are set via the R_RON resistor. Overcurrent and short-circuit protection are implemented through cycle-by-cycle current limiting. When V_FB exceeds 1.2V (V_REF) for a sustained period, the device enters an ultra-low I_Q sleep mode to improve light-load efficiency.

Applications

• Electrical appliances, energy, and garden tools
• E-bikes, electric scooters
• Motor drives, drones, and communication equipment

Key features

• COT control mode
• Wide input voltage range: 6V~100V
• Internal 3ms soft-start
• Valley current limit protection
• Input undervoltage lockout and thermal shutdown
• Adjustable frequency up to 1MHz
• 15μA no-load quiescent current
• 3μA shutdown current
• Maximum output current 1A
• 1.2V internal reference voltage
• No loop compensation required
• Internal VCC regulator
• Internal bootstrap diode
• Power good open-drain indicator
• ESOP8 package