MAX4910 Maxim, MAX4910 Datasheet - Page 9

• Manufacturer Part Number: MAX4910
• Description: The MAX4910/MAX4911/MAX4912 quad, singlepole/double-throw (SPDT), clickless audio switches feature negative signal capability that allows signals as low as VCC -5
• Manufacturer: Maxim

The MAX4910/MAX4911/MAX4912 on-resistance is
channel dependant. Channels 1 and 3 have an on-
resistance of 0.37Ω (typ), and channels 2 and 4 have
an on-resistance of 0.72Ω (typ). The on-resistance flat-
ness is guaranteed over temperature and shows mini-
mal variation over the entire voltage supply range (see
the Typical Operating Characteristics). The on-resis-
tance flatness and low-leakage features make it ideal
for bidirectional operation. The switches are bidirection-
al, so the NO_, NC_, and COM_ pins can be either
inputs or outputs.
These devices pass signals as low as V
including signals below ground with minimal distortion.
The MAX4910/MAX4911 have a 3.8kΩ (typ) shunt resis-
tor on all their NO and NC terminals to automatically
discharge any capacitance when they are not connect-
ed to COM. The MAX4912 has shunt resistors on all
NO, NC1, and NC3 terminals. The shunt resistors
reduce audible click-and-pop sounds that occur when
switching between audio sources.
Audible clicks and pops are caused when a step DC
voltage is switched into the speaker. The DC step tran-
Figure 1. Typical Application Circuit
_______________________________________________________________________________________
Click-and-Pop Suppression
Quad-SPDT, Clickless Audio Switches
MELODY IC
CODEC
CODEC
VOICE
MP3
AMP
Analog Signal Levels
with Negative Signal Handling
CC
- 5.5V,
NC1
NC3
NC2
NC4
NO1
NO3
NO2
NO4
SIGNAL CONTROL
sients can be reduced by automatically discharging the
side that is not connected to the COM terminal, reducing
any residual DC voltage and reducing clicks and pops.
The MAX4910/MAX4911/MAX4912 feature break-
before-make switching, which is configured to break
(open) the first set of contacts before engaging (clos-
ing) the new contacts. This prevents the momentary
connection of the old and new signal paths to the out-
put, reducing click-and-pop sounds.
Caution: Do not exceed the Absolute Maximum
Ratings since stresses beyond the listed ratings
may cause permanent damage to the device.
Proper power-supply sequencing is recommended for
all CMOS devices. Improper supply sequencing can
force the switch into latchup causing it to draw exces-
sive supply current. The only way out of latchup is to
recycle the power and properly reapply it. Connect all
ground pins first, then apply power to V
apply signals to NO_, NC_, and COM_. Follow the
reverse order upon power-down.
1.8V TO 5.5V
DISCHARGE
MAX4910
MAX4911
MAX4912
CONTROL/
V
CC
GND
COM1
COM3
COM2
COM4
Power-Supply Sequencing and
CB1 (CB)
CB2 (EN)
Break-Before-Make Switching
( ) IS FOR MAX4911 ONLY
SPEAKER 8Ω
Overvoltage Protection
CC
, and finally
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