TSB11LV01

3-V 1-PORT IEEE 1394-1995 CABLE TRANSCEIVER/ARBITER

SLLS232B – MARCH 1996 – REVISED MAY 1997

4

POST OFFICE BOX 655303

description (continued)

when the cable connection status indicates no cable is connected and is not debounced. The device reset

condition occurs when the RESET input terminal is asserted low. The transmitter disable and receiver disable

conditions are determined from the internal logic.

The line drivers in the TSB11LV01 operate in the high-impedance current mode and are designed to work with

external 112-

Ω line matching resistor networks. One network is provided at each end of each twisted-pair cable.

Each network is composed of a pair of series-connected 56-

Ω resistors. The midpoint of the pair of resistors

that are directly connected to the twisted-pair A-package terminals is connected to the TPBIAS voltage terminal.

The midpoint of the pair of resistors that is directly connected to the twisted-pair B-package terminals is coupled

to ground through a parallel resistance-capacitance (R-C) network with the recommended value of 5 k

Ω and

250 pF. The values of the external resistors are designed to meet the IEEE 1394-1995 standard specifications

when connected in parallel with the internal receiver circuits (see Figure 3).

An internal reference circuit (bandgap) provides stable bias voltages for the TSB11LV01 transceiver circuits.

The driver output current, along with other internal operating currents, is set by an external resistor. This resistor

is connected between terminals R1 and R0, and has a value of 6 k

Ω ±0.5%.

Two of the package terminals set up various test conditions used in manufacturing. These terminals, TESTM1

Four package terminals are inputs to set four configuration status bits in the self-identification (Self-ID) packet.

These terminals are hardwired high or low as a function of the equipment design. PC0, PC1, and PC2

(corresponds to bits 21, 22, and 23 of the Self-ID packet) are three terminals that indicate either the need for

power from the cable or the ability to supply power to the cable. The fourth terminal, C/LKON (corresponds to

bit 20 of the Self-ID packet), indicates if a node is a contender for bus manager. C/LKON may also output a

6.114-MHz

±100 ppm signal, indicating reception of a link-on packet. See Table 4-29 of the IEEE 1394-1995

standard for additional details.

In order to operate with power supplies as low as 2.7 V, this device is restricted to applications that do not provide

cable power. See Note A in clause 4.2.2.2 of the IEEE 1394-1995 standard.

When the TSB11LV01 is used in applications with a 5-V link layer controller, such as the TSB12C01A, the

BIAS–5V terminal should be connected to the link layer controller 5-V supply. Otherwise, connect this terminal

A power-down terminal (PWRDN) is provided to allow most of the TSB11LV01 circuits to be powered down to

conserve energy in battery-driven applications. A cable status terminal (CNA) provides a high output when the

twisted-pair cable port is disconnected. This output is not debounced. The CNA output can determine when to

power the device down. In the power-down mode all circuitry is disabled except the CNA detection circuitry.

If the power supply of the TSB11LV01 is removed while the twisted-pair cables are connected, the TSB11LV01

transmitter and receiver circuitry has been designed to present a high-impedance signal to the cable and not

load the TPBIAS voltage on the other end of the cable.