The M5839 is a high-performance offline PWM controller designed for low-power AC/DC applications. It is mainly used in single-phase smart meters, three-phase smart meters, chargers and power adapters.
Adopting a primary-side sensing and regulation architecture, this chip eliminates the need for TL431 and optocoupler components, simplifying the peripheral circuit design. It integrates constant current (CC) and constant voltage (CV) dual control modes. In constant-current mode, the constant current value and output power can be set via the current-limiting resistor RS connected to the CS pin. In constant-voltage mode, the INV pin samples the auxiliary winding voltage to realize output regulation. The multi-mode control balances high precision and high efficiency. Built-in line loss compensation circuitry ensures accurate output voltage.
The M5839 integrates a 900V high-voltage MOSFET with very low on-resistance. It supports wide AC input voltage ranging from 85V to 380V. No external high-voltage MOSFET is required, which effectively reduces PCB footprint. It meets the small-size and cost-effective design requirements of power supplies for single-phase and three-phase smart meters.
Suitable for low-power AC/DC applications
Single-Phase Smart Meter Power Supply
Three-Phase Smart Meter Power Supply
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Integrated 900 V high-voltage low Rds(on) MOSFET
CV and CC accuracy up to 5%
Primary-side control mode, no TL431 and optocoupler required
Flyback topology operating in discontinuous mode
Built-in soft-start function
Internal Leading Edge Blanking (LEB) circuit
Frequency dithering
CV / CC control
Adjustable constant current and output power
Integrated primary voltage sampling controller
Adjustable line loss compensation
Full set of system stability protections: UVLO under-voltage lockout, cycle-by-cycle current limit, peak current limit, thermal protection, overvoltage protection and power clamp
| Category | Parameters |
| Operating Mode |
CV / CC dual mode; Frequency Dithering; Soft-start: 10 ms; No valley switching, no burst mode; Adjustable line loss compensation; Constant current set by external resistor on CS pin |
| Response / Oscillation Frequency |
Max Operating Frequency: 60 kHz; Start-up Frequency: 14 kHz; Frequency Dithering: ±4%; Frequency constrained by load / demagnetization time to avoid entering CCM continuous mode |
| Supply Current |
Start-up Current: 5 ~ 20 µA; Operating Current: 2.5 ~ 3.5 mA; No burst mode current parameters |
| Undervoltage Lockout (UVLO) | Trigger threshold: 7.5 / 8.5 / 10 V; Recovery threshold: 13.5 / 14.5 / 16 V |
| Overvoltage Protection |
27 / 28 / 32 V; VDD Clamp Voltage: 30 / 32 / 35 V; No independent pin for output OVP adjustment |
| Feedback (FB) |
INV primary-side sensing, internal reference: 2 V (1.97 ~ 2.03 V); Error amplifier gain: 60 dB; COMP pin loop compensation; Max line loss compensation current: 42 µA; No green / burst mode threshold and no maximum duty cycle parameter
|
| Current Sensing (SEN) |
CS pin; Cycle-by-cycle and peak dual current limit; OCP Threshold: 870 / 900 / 930 mV; Leading Edge Blanking: 540 ns; OCP Delay: 150 ns; Soft-start Time: 10 ms; Constant current and power set by external RS resistor |
| Gate Drive (GATE) |
Integrated 900 V power MOSFET, Rds(on) = 4.7 Ω; VOL ≤ 1 V, VOH = 8 V; Clamp Voltage: 15 V; Rise Time: 650 ns; Fall Time: 40 ns |
| Protection Functions |
Cycle-by-cycle OCP and peak current limit, UVLO, VDD OVP, power clamp, OTP thermal protection; Protection shuts down MOS with auto-restart and soft-start; No independent output OVP function, no external OTP |
| Overtemperature Protection | Over-Temperature Protection (OTP) supported |
| Temperature Parameters | Operating Ambient Temperature: -40 ~ 105 ℃; Max Junction Temperature: 125 ℃; Storage Temperature: -40 ~ 150 ℃; Soldering Condition: 260 ℃ / 10 s |
| Energy Efficiency Standards | Frequency dithering for EMI improvement; Line loss compensation for better output voltage accuracy |
| Package Type | DIP‑7 |
Pending update...
