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目录
一,产品概述(General Description)
PWM controllers (that drives dual N-channel MOSFETs for each channel) and
The JTMA8811 is equipped with accurate sourcing cur-rent-limit, output under-voltage and output over-voltage protections, being perfect for NB applications. A 1.7ms (typ.) digital soft-start can reduce the start-up current. A soft-stop function actively discharges the output capaci-tors by the discharge device. The JTMA8811 has individual enable controls for PWM channels and LDOs. Pulling both ENPWM pin and ENLDO pin low shuts down the whole chip with low quiescent current close to zero.two low drop-out regulators as well as various protections into a chip.The PWM controllers step down high voltage of a battery to generate low-voltage for NB applications. The output of PWM1 and PWM2 can be adjusted from 2V to 5.5V by setting a resistive voltage-divider from VOUTx to GND.The linear regulators provide 5V and 3.3V output for standby power supply. The linear regulators provide up to 100mA output current. When the PWMx output voltage is higher than LDOx bypass threshold, the related LDOx regulator is shut off and its output is connected to VOUTx by internal switchover MOSFET. It can save power dissipation. The JTMA8811 provides excellent transient response and accurate DC output voltage in either PFM or PWM Mode.In Pulse-Frequency Mode (PFM), the JTMA8811 provides very high efficiency over light to heavy loads with loading-modulated switching frequencies. The Forced-PWM mode works nearly at constant frequency for low-noise requirements. The unique ultrasonic mode maintains the switching frequency above 25KHz, which eliminates noise in audio applications. The JTMA8811 is available in a TQFN4x4-24A package. 二.产品特点(Features) Wide Input Voltage Range from 6V to 25V Provide 4 Independent Outputs with ±1.5% Accu- racy Over-Temperature - PWM1 Controller with Adjustable (2V to 5.5V) Out-put PWM2 Controller with Adjustable (2V to 5.5V) Out-put 100mA Low Dropout Regulator (LDO5) with Fixed 5V Output 100mA Low Dropout Regulator (LDO3) with Fixed 3.3V Output Excellent Line/Load Regulations about ±1.5% Over-Temperature Range ±1%, (±1.5%, 50µA) 2.0V Reference Voltage Output Built-In POR Control Scheme Implemented Selectable Forced-PWM or Automatic PFM/PWM (with Selectable Ultrasonic Operation) Constant-On-Time Control Scheme with Frequency Compensation for PWM Mode Selectable Switching Frequency in PWM Mode Built-in Digital Soft-Start for PWM Outputs and Soft- Stop for PWM Outputs and LDO Outputs Integrated Bootstrap Forward P-CH MOSFET High Efficiency over Light to Full Load Range (PWMs) Built-in Power Good Indicators (PWMs) Independent Enable Inputs (PWMs, LDO) 70% Under-Voltage and 125% Over-Voltage Protec-tions (PWM) (责任编辑：oumao18) |
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