MAX16913 Datasheet, PDF (7/10 Pages) Maxim Integrated Products – Remote Antenna Current-Sense Amplifier and Switches

Remote Antenna Current-Sense
Amplifier and Switches
TURN-ON INTO A HARD SHORT CIRCUIT
2 x I_SC
I_SC
LOAD CURRENT
t_BLANK
SHDN
SC
t_RETRY
RETRY
TURN-ON INTO A TEMPORARY SHORT CIRCUIT
2 x I_SC
I_SC
LOAD CURRENT
t_BLANK
t_RETRY
SHDN
SC
RETRY
Figure 1. Short-Circuit Timing Diagram
switch is zero (see Figure 1). If the load current is
greater than I_SC, but does not reach the 2 x I_SC thresh-
old, the t_BLANK timer still begins counting (see Figure
2). The resistor across IN and SENS sets I_SC to a typi-
cal value of 100mV/R_SENSE (Ω). Blanking time and retry
time have fixed values of 100ms (min) and 1500ms
(min), respectively.
Short-to-Battery Detection
It may happen that OUT is shorted to the battery due to
a fault in the system. The MAX16913/MAX16913A
detect this failure by comparing the OUT voltage and
the IN voltage before the switch turns on. Every time
the switch turns on, such as at the end of the retry time,
or once the thermal shutdown condition disappears,
the short-to-battery detection is performed. At this
point, if the device detects any failure, the switch stays
off, and both SC and OL assert low (see Table 1).
Thermal Shutdown
Thermal shutdown circuitry protects the devices from
overheating. The switch turns off immediately when the
junction temperature exceeds +150°C (min) (see Table
1). The switch turns on again after the device tempera-
ture drops by approximately 15°C (typ).
Shutdown (SHDN)
The MAX16913/MAX16913A feature an active-high con-
trol input (SHDN) to put the devices in a low-power shut-
down mode. The devices turn off and consume only 5µA
(max) of shutdown current when SHDN is driven high.
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