TS4962M

Application Information

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5.5

Decoupling of the circuit

The TS4962M has a typical switching frequency at 250kHz and output fall and rise time about

5ns. Due to these very fast transients, careful decoupling is mandatory.

A 1µF ceramic capacitor is enough, but it must be located very close to the TS4962M in order

to avoid any extra parasitic inductance created an overly long track wire. These parasitic

inductances introduce, in relation with dI/dt, overvoltage that decreases the global efficiency

and may cause, if this parasitic inductance is too high, a TS4962M breakdown.

In addition, even if a ceramic capacitor has an adequate high frequency ESR value, its current

capability is also important. A 0603 size is a good compromise, particularly when 4

Ω load is

used.

Another important parameter is the rated voltage of the capacitor. A 1µF/6.3V capacitor used at

5V, lose about 50% of its value. In fact at 5V power supply voltage, we have a decoupling value

frequency region, this capacitor variation becomes decisive. In addition, less decoupling means

higher overshoot that can be problematic if they reach the power supply AMR value (6V).

5.6

When the standby is released to set the device ON, there is a wait of about 5ms. The TS4962M

has an internal digital delay that mutes the outputs and releases them after this time in order to

avoid any pop noise.

5.7

Shutdown time

When the standby command is set, the time required to put the two output stages into high

impedance and to put the internal circuitry in shutdown mode, is about 5ms. This time is used

to decrease the gain and avoid any pop noise during shutdown.

5.8

Consumption in shutdown mode

Between the shutdown pin and GND there is an internal 300k

Ω resistor. This resistor force the

TS4962M to be in shutdown when the shutdown input is leaved floating.

However, this resistor also introduces additional shutdown power consumption if the shutdown

pin voltage is not 0V.

Referring to Table 2: Operating conditions on page 2, with 0.4V shutdown voltage pin for

example, we have 0.4V/300k

Ω = 1.3µA in typical (0.4V/273kΩ = 1.46µA in maximum) to add to

the shutdown current specified in the tables in Table 4 on page 4.