DIO2140

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© 2022 DIOO MICROCIRCUITS CO., LTD

DIO2140• Rev. 1.5

Input Resistors (RI)

The input resistors set the gain of the amplifier according to Equation 1.

Resistor matching is very important in fully differential amplifiers. The balance of the output on the reference

voltage depends on matched ratios of the resistors. CMRR, PSRR, and cancellation of the second harmonic

distortion diminish if resistor mismatch occurs. Therefore, it is recommended to use 1% tolerance resistors or

better to keep the performance optimized. Matching is more important than overall tolerance. Resistor array with

1% matching can be used with a tolerance greater than 1%.

Decoupling Capacitor (CS)

The DIO2140 is a high-performance class-D audio amplifier that requires adequate power supply decoupling to

ensure the efficiency is high and total harmonic distortion (THD) is low. For higher frequency transients, spikes,

or digital hash on the line, a good low equivalent-series-resistance (ESR) ceramic capacitor, typically 1 μF,

placed as close as possible to the device VDD lead works best.

Input Capacitors (CI)

The DIO2140 does not require input coupling capacitors if the design uses a different source that is biased from

0.5 V to VDD - 0.8 V. If the input signal is not biased within the recommended common-mode input range, if

needing to use the input as a high pass filter, or if using a single-ended source, input coupling capacitors are

required. The input capacitors and input resistors form a high-pass filter with the corner frequency, fC, determined

in Equation 2,

fc =

)

2

(

1

I

I

C

R



Thermal Protection Function

This is the function to establish the thermal protection mode when detecting excessive high temperature of the

DIO2140 itself. In the thermal protection mode, the differential output terminal becomes Weak Low state. And

when the DIO2140 gets out of such condition, the protection mode is canceled.

)

(

Ω

150

2

V

V

R

k

I





Gain

1

2