10

NXP Semiconductors

80310

5.3.1

Supply voltage: filter/divider, bandgap, and POR

An input filter and divider provides a clean image of the battery to the digital regulation loop circuit. The divider ratio can be adjusted by

OTP. The supply block provides the voltages for the internal blocks of the 80310:

• Main logic

• Analog permanently powered or not

• LIN transceiver

• Charge pump

The purpose of the POR block is to generate a clean power-on signal to the main logic. The Bandgap block provides the voltage and

current references for the other blocks.

5.3.2

Power stage: charge pump, drive and protection, current measurement

The power stage of the circuit consists of the gate driver with a charge pump and protection to control a low side driver switching the

excitation current. A short-circuit is instantaneously detected and the excitation current is turned off until the next regulation cycle. A

freewheeling diode is inserted between the EXC and GND pins, across the excitation coil for the energy recirculation. The current

measurement block provides a proportional value of the excitation current flowing in the high-side switch.

5.3.3

Logic and control

Digital

The digital block gathers all the digital functions of the device. The main functionality is described in the device operation paragraph.

Clock

This block is the clock reference for the digital block. The oscillator generates a 5.0 V square wave at the frequency of 4.0 MHz in Normal

mode operation.

OTP

This block allows an easy configuration and adjustment of the circuit. A set of NVM bits can be programmed during the factory test phase.

They are described in Table 6.

Phase low & high

The phase detector monitors the Phase inputs and sends filtered low and high levels to the main logic when either one has reached the

detection level (1.0 V at startup and 8.0 V afterwards).

A/D converter

The analog to digital converter is used in the voltage regulation loop, in the current feedback and in temperature measurement.

LIN

This block allows the LIN bus transmission and reception.

T° measurement

This block generates a voltage proportional to the die temperature. This voltage is converted by the ADC into a digital number to be

transmitted via the LIN bus to the controller.