AS1712 查看數據表（PDF） - austriamicrosystems AG

零件编号

产品描述 (功能)

生产厂家

AS1712

High-Output-Drive, 10MHz, 10V/µs, Rail-to-Rail I/O Op Amps with Shutdown

austriamicrosystems AG 

AS1710/AS1712

Data Sheet - Application Information

60mW Single-Supply Stereo Headphone Driver

Two AS1710 amplifiers can be used as a single-supply, stereo headphone driver. The circuit shown in Figure 22 can

deliver 60mW per channel with 1% distortion from a single 5V supply.

Figure 22. Stereo Headphone Driver Application (with Coupling Capacitor)

RF

Audio In CIN

RIN

Left

VBIAS

Audio In

Right

CIN

RIN

–

AS1710

+

+

AS1710

–

COUT

+

Headphone Jack

to 32Ω Stereo

Headset

COUT

+

RF

In Figure 22, CIN and RIN form a high-pass filter that removes the DC bias from the incoming signal. The -3dB point of

the high-pass filter is given by:

f-3dB = 1/(2πRINCIN)

(EQ 4)

Choose gain-setting resistors RIN and RF according to the amount of desired gain, keeping in mind the maximum out-

put amplitude.

COUT blocks the DC component of the amplifier output, preventing DC current flowing to the load. The output capacitor

and the load impedance form a high-pass filter with the -3dB point determined by:

f-3dB = 1/(2πRLOADCOUT)

(EQ 5)

For a 32Ω load, a 100µF aluminum electrolytic capacitor gives a low-frequency pole at 50Hz.

Rail-to-Rail Input Stage

The AS1710/AS1712 CMOS op amps have parallel connected N- and P-channel differential input stages that combine

to accept a common-mode range extending to both supply rails. The N-channel stage is active for common-mode input

voltages typically greater than (VSS + 1.2V), and the p-channel stage is active for common-mode input voltages typi-

cally less than (VDD - 1.2V).

Rail-to-Rail Output Stage

The minimum output is within millivolts of ground for single- supply operation, where the load is referenced to ground

(VSS). Figure 23 shows the input voltage range and the output voltage swing of an AS1710 connected as a voltage fol-

lower. The maximum output voltage swing is load dependent although it is guaranteed to be within 500mV of the posi-

tive rail (VDD = 2.7V) even with maximum load (32Ω to ground).

www.austriamicrosystems.com

Revision 1.04

10 - 17

Share Link: