Reversed current protection circuit and high maximum input voltage provide cost reduction and space saving to various equipments
November 24, 2009
New Japan Radio releases the NJM2837, 20V maximum input-voltage and 1A output-current LDO
November 24, 2009 - New Japan Radio Co., Ltd has introduced to the market, the NJM2837, 20V maximum input-voltage and 1A output-current LDO, suitable for power unit of CCD in DSC (Digital Still Camera), TV/DVD and motor driving.
[Background of development]
Recently, the power units of CCD, AV (Audio-Visual) devices and motor driving mounted in OA (Office Automation) equipments demand 20V maximum input-voltage LDO (Low Dropout voltage regulator). Further these equipments are also required cost-down and space saving. To meet these needs, New Japan Radio Co., Ltd. has developed the NJM2837.
The NJM2837 consists of constant-voltage circuit, ON/OFF control circuit, reversed current protection circuit, over-current protection circuit and thermal overload protection circuit.
- 1.Built-in reversed current protection circuit
- For stable operation, general LDO is usually required capacitor connecting at output terminal. There is, however, a risk to destroy it from reverse current by discharge offset voltage. Therefore, it is necessary to add a SBD (Schottky barrier diode) as a protection circuit. The NJM2837 has a built-in protection circuit, and it becomes the SBD unnecessary.
- 2.High maximum input voltage and wide output voltage range
- The NJM2837 has high maximum input voltage 20V. Therefore it is suitable for the power unit of CCD, AV devices and motor driving in OA equipments, required high maximum input voltage. Furthermore, it also has wide output voltage range from 2.4V to 15.0V by 0.1V step, so it can respond to various specifications flexibly.
- 3.Using small size 2.2 µF ceramic capacitor is available
- The NJM2837 has realized using ceramic capacitor as output capacitor, by circuit layout optimization. It provides the cost down and space saving of the mounted board.
||20V maximum input-voltage and 1A output-current LDO
||CCD power unit in DSC and DVC
Power unit of AV devices Power unit of motor driving in OA equipments
[Features & Characteristics]
- Maximum Input Voltage 20V
- Wide Output Voltage Range 2.4V to 15V
- High precision output voltage Vo±1.0%
- Maximum output current Io(max.) = 1A
- Using ceramic capacitor available
- High ripple rejection ratio 75dB typ. f=1kHz
- Low Noise VNO=45µVrms typ.
- ON/OFF Control
- Built-in reverse current protection circuit
- Built-in thermal overload protection circuit
- Built-in over-current protection circuit
- Bipolar technology
- Package outline TO-252-5(6.54×9.68×2.29mm typ.)
- Engineering Samples(ES) : already available from October 2009
- Mass Production(MP) : already available from November 2009