Datasheet

Detailed Description
The MAX3054/MAX3055/MAX3056 interface between
the protocol controller and the physical wires of the bus
lines in a CAN. The devices provide differential transmit
capability and switch to single-wire mode if certain fault
conditions occur (see the Failure Management section).
The MAX3054/MAX3055/MAX3056 guarantee full wake-
up capability during failure modes.
The extended fault-protection range of CANH and CANL
bus lines (±80V). A current-limiting circuit protects the
transmitter output stage against overcurrent faults. This
feature prevents destruction of the transmitter output
stage. If the junction temperature exceeds a value of
approximately +165°C, the transmitter output stages are
disabled. The CANH and CANL lines are also protected
against electrical transients, which can occur in harsh
environments.
The transceiver provides three low-power modes that
can be entered and exited through pins STB and EN. An
output INH pin can be used for deactivation of an external
voltage regulator.
The MAX3054/MAX3055/MAX3056 are designed to pro-
vide optimal operation for a specified data rate. The
MAX3054 is ideal for high data rates of 250kbps. The
MAX3055 is used for data rates of 125kbps and the
MAX3056 is designed for 40kbps applications. For the
40kbps and 125kbps versions, the built-in slope-control
feature allows the use of unshielded cables and receiver
input filters guarantee high noise immunity.
Normal Operation Mode
Transmitter
The transmitter converts a single-ended input (TXD) from
the CAN controller to differential outputs for the bus lines
(CANH, CANL).
Receiver
The receiver takes differential input from the bus lines
(CANH, CANL) and converts this data as a singleended
output (RXD) to the CAN controller. It consists of a com-
parator that senses the difference ΔV = (CANH - CANL)
with respect to an internal threshold.
BATT
The main function of BATT is to supply power to the
device when +12V voltage is supplied.
PIN NAME FUNCTION
1 INH Inhibit Output. Inhibit output is for switching an external voltage regulator if a wake-up signal occurs.
2 TXD Transmit Data Input
3 RXD Receive Data Output
4 ERR
Error. Wake-up and power-on indication output; active low in normal operating mode when the bus has
a failure and in low-power modes (wake-up signal or power-on standby).
5 STB
Standby. The digital control signal input (active low) denes, together with input signal on pin EN, the
state of the transceiver (in normal and low-power modes).
6 EN
Enable. The digital control signal input denes, together with input signal on pin STB, the state of the
transceiver (in normal and low-power modes).
7 WAKE Wake-Up. Local wake-up signal input; falling and rising edges are both detected.
8 RTH Termination Resistor. Termination resistor connection for CANH bus.
9 RTL Termination Resistor. Termination resistor connection for CANL bus.
10 V
CC
Supply Voltage. Bypass to ground with a 0.1µF capacitor.
11 CANH High-Level Voltage Bus Line
12 CANL Low-Level Voltage Bus Line
13 GND Ground
14 BATT Battery Supply. Bypass to ground with a 0.1µF capacitor.
MAX3054/MAX3055/
MAX3056
±80V Fault-Protected/Tolerant CAN Transceiver
www.maximintegrated.com
Maxim Integrated │ 11
Pin Description