The AC-coupling capacitor forms a high-pass filter with the load. If a smaller value capacitor is selected, lower audio frequencies will be attenuated. Hence, a large AC-coupling capacitor is needed to block the DC bias from the DAC output. The cutoff frequency is calculated as follows:

Figure 2-12 AC Equivalent Circuit of Output Pin

For headset (16–32Ω) applications: Use ≥470µF (32Ω) and ≥680–1000µF (16Ω) to maintain F_c = 10–15Hz.

For Line-out loads (≥10kΩ): The capacitor can be small (typically 1–4.7µF).

To avoid the big/expensive caps (and optimize BOM):

1. Use pseudo-differential / cap-less drive (OUTxP/OUTxM both driven): no series caps needed; best for headphones and keeps bass. Configure OUT1x_CFG for pseudo-differential.
2. If single-ended is required:

• Raise the load impedance (use a line receiver/headphone amp with high Z_in) so the coupling cap can be 1–4.7µF instead of hundreds of µF
• Select the smallest cap that hits your bass target:
• 32Ω: 470µF approximately 10.6Hz; 680µF approximately 7.4Hz; 1000µF approximately 5Hz
• 16Ω: 680µF ≈ 14.7Hz; 1000µF ≈ 10Hz.
• Prefer aluminum and polymer electrolytic, + terminal toward the DAC (positive common-mode)

3. For line-level outputs:

• Use 1–2.2µF X7R MLCC (cost-effective) or film for lowest THD. 47 µF is overkill for ≥10kΩ loads
• Or DC-couple if the receiver tolerates the DAC V_CM.