Microchip Debuts a High-Precision Voltage Reference IC for Automotive Applications
The new AEC-Q100 qualified device offers high reliability and low drift over an extended temperature range.
The MCP1502, part of Microchip’s family of voltage reference (Vref) products, operates over the same -40°C to +125°C temperature range as does its predecessor, the MCP1501. The new unit features a Vref with a maximum temperature coefficient of 7ppm/°C over that entire temperature range, which represents a significant improvement over the 50 ppm/°C specification of the previous MCP1501.
The MCP1502. Image courtesy of Microchip
What Customers Seek in Vref Devices
As described by Fanie Duvenhage, vice president of Microchip’s mixed-signal and linear devices business unit, “Microchip looked at the top four aspects that customers were requesting in a Vref and made a product that combines high reliability, small package size and high performance at a very cost-effective price.” He goes on to say that, “This combination of features at this price is unmatched by competitors, especially when you add our experience in serving customers in the automotive and aerospace industries who require robust products for harsh environments.”
Features Common to Both Devices
The new MCP1502 is largely based on the architecture of the MCP1501, a proven device that has been on the market for over five years, It would appear that the most significant difference between the units is the significantly different maximum temperature coefficients. Otherwise, aside from the two extra package options available for the MCP1501 and the slight pinout differences that they present, the units are quite similar. Microchip provides detailed datasheets for both the MCP1501 and the MCP1502.
Both the MCP1501 and the MCP1502 are buffered voltage references that feature sinking and sourcing currents of 20 mA with each offering eight different voltage variants. These are 1.024V, 1.250V, 1.800V, 2.048V, 2.500V, 3.000V, 3.300V and 4.096V.
The voltage reference devices feature initial accuracy of 0.1% and typical no-load currents of 140μA. Maximum line and load regulations are 50 ppm/V and 40 ppm/mA. For the 1.024V variants of both devices, output noise is 30 μVRMS over a 0.1 Hz to 10 kHz bandwidth.
Circuit Description and Operations
VDD is the power supply pin. The maximum voltage and current are 5.5V and 30mA, respectively. Minimum voltage is dependent on the magnitude of the output Vref. SHDN, active low, serves to shut down the output.
Block diagram for the MCP1501 and the MCP1502. Image courtesy of MCP1502 datasheet
Both units are low-drift, bandgap-based buffered voltage references. Because the bandgap employs chopper-based amplifiers, the drift is effectively reduced to zero.
- Industrial Controls
- Electric Vehicle Battery Management Systems
- Medical Equipment
- Precision Data Acquisition Systems
- Battery-Powered Devices
- High-Resolution Data Converters
- Both the MCP1501 and the MCP1501 are available in 6-lead SOT-23 packages
- The MCP1501 is also offered in 8-lead SOIC packages and in 8-lead 2 x 2mm WDFN packages
- The versions of the MCP1501 and the MCP1501 furnished in SOT-23 packages are grade 1 AEC-Q100 qualified
- ROHS qualified
- EFUP (China) qualified