MAX4896ATP+ Maxim Integrated Products, MAX4896ATP+ Datasheet - Page 10

• Manufacturer Part Number: MAX4896ATP+
• Description: IC RELAY/LOAD DRVR 8CHAN 20-TQFN
• Manufacturer: Maxim Integrated Products
• Type: Relay/Load Driverr

Specifications of MAX4896ATP+

• Input Type: SPI
• Number Of Outputs: 8
• On-state Resistance: 3 Ohm
• Current - Output / Channel: 410mA
• Current - Peak Output: 960mA
• Voltage - Supply: 2.7 V ~ 5.5 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 20-TQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

The minimum fault-filtering time helps mask short-dura-
tion fault conditions, such as driving highly capacitive
loads.
The typical diagnostics software routine works as follows:
Use Table 3 to diagnose the output state.
To reduce processor overhead, an interrupt-based
diagnostics routine is possible. The diagnostics routine
will analyze diagnostics data only when the FLAG out-
put triggers an interrupt.
The MAX4896 channels (OUT_) are protected against
short-circuits conditions. When the channel’s output
current exceeds the current-limit threshold (I
longer than the minimum fault-filtering time (t
min), the short-circuit protection is activated. The short-
circuit protection behavior is determined by the logic
level at SPLD. When SPLD = high, an overloaded chan-
nel remains in a current-limited state until the short-cir-
cuit condition is removed or thermal shutdown is
reached. This allows the operation of loads where the
inrush currents may exceed the MAX4896 internal cur-
rent limit.
When SPLD = low, an overloaded channel immediately
turns off (latched-off). When a shorted output is latched
off, the channel can be turned back on after the next
serial input data is latched into the MAX4896.
The MAX4896 features an output pulldown current
source, along with a voltage comparator, to detect an
open-load fault condition. To enable the open-load
detection function, PDCD must be low. The voltage at
OUT_ is compared with the diagnostics threshold volt-
age (V
condition exists.
10
• Write data to the MAX4896
• Wait for t
• Write same data to the MAX4896 and read out the
Output Short-Circuit/Current-Limiting Protection
data is ready and valid
diagnostics data from the shift register
______________________________________________________________________________________
DS(OL)
Space-Saving, 8-Channel Relay/Load Driver
) to determine whether a open-load fault
D(FAULT)
maximum to ensure diagnostics
Open-Load Detection
D(FAULT)
LIM
) for
If the junction temperature exceeds +160°C, all outputs
are switched off immediately (no filtering time) and
FLAG asserts. The hysteresis is approximately +20°C,
disabling thermal shutdown once the temperature
drops below +140°C.
The MAX4896 features an asynchronous reset input
that allows the user to simultaneously turn all outputs off
using a single control line. Drive RESET low to clear all
latches and registers, and to turn off all outputs. While
RESET is low, the OUT pulldown currents are disabled,
regardless of the state of PDCD.
FLAG is an open-drain latched output that can be con-
nected to a µP interrupt and pulls low whenever a fault
condition (short-circuit and/or open-load) is detected in
any of the eight outputs for longer than the minimum
fault-filtering time (t
diately, (no filtering time), when a thermal-shutdown
fault condition is detected. The latch FLAG deasserts
on CS rising edge.
The MAX4896 features a digital output (DOUT) that pro-
vides a simple way to daisy chain multiple devices. This
feature allows the user to drive large banks of relays
using only a single serial interface. To daisy chain multi-
ple devices, connect all CS inputs together and con-
nect the DOUT of one device to the DIN of another
device (see Figure 3). During operation, a stream of
serial data is shifted through all the MAX4896s in
series.
Each output features an output protection clamp, limit-
ing the OUT voltage to 65V (typ). The clamp protects
against voltage transient when driving inductive loads.
Applications Information
Inductive Kickback Protection
D(FAULT)
min). FLAG asserts imme-
Thermal Shutdown
Daisy Chaining
FLAG Output
RESET