GENERAL DEscriptION

The SGM4918 is stereo headphone amplifier which is designed for portable applications and can operate from a 2.7V to 5.1V single supply. Capless design can produce a ground-referenced output from a single power supply, and can eliminate output DC-blocking capacitors for less-component height and low-cost. For SGM4918B, the internal gain setting (-2V/V) is to further reduce component count. For SGM4918A, the gain can be adjusted by external feedback resistors.

The SGM4918 has low current 5.8mA at 5V supply, low 0.03% THD+N, 80mW per channel into 32Ω load from 5V power supply at THD+N = 0.1%. The high supply rejection ratio (PSRR) of -78dB at 217Hz allows the device to operate from noisy digital supplies without an additional linear regulator. The device provides short-circuit and thermal-overload protections. Build-in shutdown control also helps for pop/click-free on/off control.

The SGM4918 is available in a Green TQFN-3×3-10L package. It operates over an ambient temperature range of -40℃ to +85℃.

FEATURES

• Supply Voltage Range: 2.7V to 5.1V

• SGM4918A: External Feedback Gain Network

  SGM4918B: Fixed -2V/V Gain

• Capless Structure

  Eliminates Ground-Referenced Outputs

  Eliminates Output DC-Blocking Capacitors

  Provides Flat Frequency Response

• 80mW into 32Ω Load from 5V Power Supply at THD+N = 0.1% (Typical, per Channel)

• THD+N = 0.03% (f = 1kHz)

• High PSRR: -78dB (at 217Hz)

• Current: 5.8mA (TYP)

• Shutdown Control

• Short-Circuit and Thermal-Overload Protections

• Under-Voltage Lockout Function

• -40℃ to +85℃ Operating Temperature Range

• Available in a Green TQFN-3×3-10L Package

APPLICATIONS

Smart Phones

Portable Audio Equipment

Notebook PCs

PDAs