Datasheet

MAX14979E
High-Bandwidth, ±15kV ESD Protection
LVDS Switch
7
Detailed Description
The MAX14979E is a high-speed analog switch targeted
at LVDS and other low-voltage switching up to 600MHz.
In a typical application, the MAX14979E switches two
sets of LVDS sources to a laptop LVDS panel. For extra
security, the MAX14979E is protected against Q15kV
ESD shocks. See the Functional Diagram.
With its low resistance and capacitance, as well as high-
ESD protection, the MAX14979E can be used to switch
most low-voltage differential signals, such as LVDS and
LVPECL, as long as the signals do not exceed the maxi-
mum ratings of the device.
The MAX14979E switches provide low capacitance and
on-resistance to meet low insertion loss and return-loss
specifications. The MAX14979E has three additional
AUX switches.
Digital Control Inputs
The MAX14979E provides a single digital control SEL.
SEL controls the switches as well as the AUX switches,
as shown in Table 1.
Analog-Signal Levels
The on-resistance of the MAX14979E is very low and
stable as the analog input signals are swept from ground
to V+ (see the Typical Operating Characteristics). The
switches are bidirectional, allowing COM_ _ and NC_ _/
NO_ _ to be configured as either inputs or outputs.
ESD Protection
The MAX14979E is characterized using the HBM for
Q15kV of ESD protection. Figure 5 shows the HBM. This
model consists of a 100pF capacitor charged to the ESD
voltage of interest, which is then discharged into the test
device through a 1.5kI resistor. All signal and control
pins are ESD protected to Q15kV HBM.
Pin Description (continued)
Figure 5. Human Body ESD Test Model (MIL-STD-883, Method
3015)
CHARGE-CURRENT
LIMIT RESISTOR
DISCHARGE
RESISTANCE
STORAGE
CAPACITOR
C
s
100pF
R
C
1MΩ
R
D
1500Ω
HIGH-
VOLTAGE
DC
SOURCE
DEVICE
UNDER
TEST
PIN NAME FUNCTION
22 NC2+ Normally Closed LVDS Differential Terminal for Switch 2
23 NO1- Normally Open LVDS Differential Terminal for Switch 1
24 NO1+ Normally Open LVDS Differential Terminal for Switch 1
25 NC1- Normally Closed LVDS Differential Terminal for Switch 1
26 NC1+ Normally Closed LVDS Differential Terminal for Switch 1
27 SEL Select Input. SEL selects switch connection. See Table1.
28 NO0- Normally Open LVDS Differential Terminal for Switch 0
29 NO0+ Normally Open LVDS Differential Terminal for Switch 0
30 NC0- Normally Closed LVDS Differential Terminal for Switch 0
31 NC0+ Normally Closed LVDS Differential Terminal for Switch 0
32 AUX2 AUX2 Output. Drive SEL high (SEL = 1) to connect AUX0 to AUX2.
33 AUX1 AUX1 Output. Drive SEL low (SEL = 0) to connect AUX0 to AUX1.
34 AUX0 AUX0 Input
35 V+
Positive-Supply Voltage Input. Bypass V+ to GND with a 0.1FF ceramic capacitor.
36 COM0+ Common LVDS Differential Terminal for Switch 0
— EP Exposed Pad. Connect exposed pad to GND or leave it unconnected.