Overview
The NCP45491XMNTWG, produced by onsemi, is a high-performance monolithic IC designed to monitor bus voltage and current on four high-voltage power supplies simultaneously. This device translates and scales the high-voltage bus and shunt voltages to a low-voltage power domain, multiplexing them onto a single differential output for external measurement by common ADCs. It can operate either standalone or in pairs, allowing for the monitoring of up to eight separate high-voltage power supplies.
Key Specifications
| Parameter | Symbol | Min | Typ | Max | Unit |
|---|---|---|---|---|---|
| Supply Voltage Range | VCC | -0.3 | 5.5 | V | |
| Shunt Input Voltage Range | VSH_IN_X | -0.3 | 30 | V | |
| Bus Input Voltage Range | VBS_IN | -0.3 | 30 | V | |
| Operating Temperature Range | TA1 | -40 | 105 | °C | |
| Maximum Junction Temperature | TJ | 125 | °C | ||
| Thermal Resistance, Junction-to-Air | RθJA | 40 | °C/W | ||
| Thermal Resistance, Junction-to-Case (VIN Paddle) | RθJC | 5 | °C/W | ||
| ESD Capability, Human Body Model | ESDHBM | >2.0 kV | |||
| ESD Capability, Charged Device Model | ESDCDM | >0.5 kV |
Key Features
- Translates and scales shunt and bus voltages up to 26 V.
- Monitors four high-voltage power supplies simultaneously.
- Can be paired to monitor up to eight separate high-voltage power supplies.
- Very low power-down current.
- All channels individually gain programmable by external resistor selection.
- Fast settling time.
- Real-time indication of all bus voltages valid.
- Adjustable output common-mode voltage adapts to most external ADCs.
- Lead-free device.
Applications
- Computers and Notebooks.
- Graphical Cards.
- Power Management/Power Control Loops.
- Battery Chargers.
Q & A
- What is the primary function of the NCP45491XMNTWG?
The NCP45491XMNTWG is designed to monitor bus voltage and current on four high-voltage power supplies simultaneously, translating and scaling these voltages to a low-voltage power domain for external measurement.
- What is the maximum voltage range for the shunt input?
The shunt input voltage range is from -0.3 V to 30 V.
- Can the NCP45491XMNTWG operate in different configurations?
- What is the operating temperature range of the device?
The operating temperature range is from -40°C to 105°C.
- How does the device handle thermal dissipation?
Thermal dissipation is minimal since the load current does not flow through the NCP45491. Connecting the GND pad to a ground plane is sufficient.
- What is the purpose of the BS_OK pin?
The BS_OK pin provides a real-time indication that VCC and all bus voltages are valid, remaining low until all used BS_INx pins are above a user-defined threshold voltage.
- How is the common-mode voltage of the differential output amplifier set?
The common-mode voltage is established by the voltage on the CM_REF_IN pin.
- What are the key considerations for the physical layout of the NCP45491XMNTWG?
Correct physical layout is crucial, including using wide and short traces for bus voltage paths, proper 4-wire Kelvin connection to the Rshunt resistor, and keeping decoupling capacitors close to the VCC pin.
- What are the typical applications of the NCP45491XMNTWG?
Typical applications include computers and notebooks, graphical cards, power management/power control loops, and battery chargers.
- What is the ESD capability of the NCP45491XMNTWG?
The device has an ESD capability of more than 2.0 kV for the Human Body Model and more than 0.5 kV for the Charged Device Model.
