Figure 22: Ferrite Bead Filter to Reduce EMI

Shutdown Operation

In order to reduce power consumption while the device is not in use, the HM2010 includes shutdown circuitry

to de-bias all the internal circuitry when the SHDN pin is pulled low. During shutdown, the supply current of

the HM2010 is reduced less than 0.1µA, typically.

Under Voltage Lockout (UVLO)

The HM2010 incorporates circuitry designed to detect a low supply voltage. When the supply voltage drops

below 2.0V (typical), the HM2010 goes into shutdown mode. The device will emerge out of the shutdown

mode and resume its normal operation only when the supply voltage is restored to above 2.2V (typical) and

the SHDN pin pulled high.

Short-circuit Auto-Recovery

When an over-current or short-circuit event occurs, the HM2010 goes into shutdown mode. During shutdown,

the HM2010 activates auto-recovery process whose aim is to return the device to normal operation once the

fault condition is removed. This process repeatedly examines whether the fault condition persists, and

returns the device to normal operation immediately after the fault condition is removed. This feature helps

protect the device from large currents and maintain long-term reliability while removing the need for

external system interaction to resume normal operation.

Over Temperature Protection

Thermal protection on the HM2010 prevents the device from being damaged when the internal die

temperature exceeds 160°C. Once the die temperature exceeds the prescribed value, the device will enter

into shutdown state and the outputs are disabled. This is not a latched fault. The thermal fault cleared once

the temperature of the die decreased by 30°C. This large hysteresis will prevent it from generating motor

boating sound and allow the device resume normal operation without the need for external system

interaction.

POP and Click Circuitry

The HM2010 contains circuitry to minimize turn-on and turn-off transients or “click and pops”, where turn-on

refers to either power supply turn-on or device recover from shutdown mode. When the device is turned on,

the amplifiers are internally muted. An internal current source ramps up the internal reference voltage. The

device will remain in mute mode until the reference voltage reach half supply voltage, 1/2 VDD. As soon as

the reference voltage is stable, the device will begin full operation. For the best power-off pop performance,

the amplifier should be set in shutdown mode prior to removing the power supply voltage.