SLAU472C February 2013 – November 2023 TAS2505 , TAS2505-Q1
The TAS2505 features a mono headphone driver (HPOUT) that can deliver up to 28 mW channel, at 1.8-V supply voltage, into a 16-Ω load. The headphones are used in a single-ended configuration where an ac-coupling (dc-blocking) capacitor is connected between the device output pins and the headphones. The headphone driver also supports 32-Ω and 10-kΩ loads without changing any control register settings.
The headphone driver can be configured to reduce the power consumption in the half drive ability mode by writing 1 to page 1, register 10, bits D2 = 1, also in this mode the headphone driver can support lineout-drive as well.
The common-mode voltage is set to ≤ AVDD/2.
The headphone driver can be powered on by writing to page 1, register 9, bit D5. The HPOUT output driver gain can be controlled by writing to page 1 / register 16 bits D5–D0, and it can be muted by writing to page 1, register 16, bit D6.
The TAS2505 has a short-circuit protection feature for the headphone drivers, which is always enabled to provide protection. The output condition of the headphone driver during short circuit can be programmed by writing to page 1, register 11, bit D1. If D1 = 0 when a short circuit is detected, the device limits the maximum current to the load. If D1 = 1 when a short circuit is detected, the device powers down the output driver. The default condition for headphones is the current-limiting mode. For a short circuit on the channel, the output is disabled and a status flag is provided as read-only bits on page 0 / register 44, bit D7. If shutdown mode is enabled, then as soon as the short circuit is detected, page 0, register 9, bit D5 (for HPOUT) clears automatically. Next, the device requires a reset to re-enable the output stage. Resetting can be done in two ways. First, the device master reset can be used, which requires either toggling the RST pin or using the software reset. If master reset is used, it resets all of the registers. Second, a dedicated headphone power-stage reset can also be used to re-enable the output stage, and that keeps all of the other device settings. The headphone power stage reset is done by setting page 1, register 9, bit D5 for HPOUT. If the fault condition has been removed, then the device returns to normal operation. If the fault is still present, then another shutdown occurs. Repeated resetting (more than three times) is not recommended, as this could lead to overheating.