TI380C60A Datasheet, PDF (2/16 Pages) Texas Instruments – CMOS TOKEN-RING INTERFACE DEVICE

TI380C60A
CMOS TOKEN-RING INTERFACE DEVICE
SPWS033 – DECEMBER 1996
description (continued)
The TI380C60A can function as a stand-alone device because the digital PLL is self-contained and requires
no additional circuits for frequency management. Using the device in this manner in the repeat mode provides
a highly integrated token-ring repeater with no additional active components needed for wiring center
applications.
The TI380C60A is available in a 52-lead 1,0-mm plastic quad flatpack and is characterized for operation from
0°C to 95°C with a typical power dissipation of 600 mW.
Pin Functions
PIN
NAME
NO.
I / O / E† TYPE‡
DESCRIPTION
ATEST
33
E
N Analog test. ATEST should be left unconnected.
DRVR+
DRVR–
5
6
I
I
D
D
Differential driver data inputs. DRVR+ and DRVR– receive the ’380C2x transmit data.
EQ +
EQ –
41
E
N Equalization / gain points. EQ+ and EQ- provide connections to allow frequency tuning of the
40
E
N equalization circuit.
FRAQ
Frequency acquisition control. FRAQ is driven by the ’380C2x or can be tied low for repeater
10
I
TTL
applications.
H = Clock-recovery PLL is initialized
L = Normal operation
IREF
35
E
N
Internal reference. IREF allows the internal bias current of analog circuitry to be set by way of an
external resistor.
NABL
Output-enable control. NABL can be used in token-ring / Ethernet™ applications to disable the
token-ring function. (See Note 1)
13
I
TTL
H = TI380C60A operates normally
L = All outputs are driven to the high-impedance state, except XMT+ / XMT–, which are
driven low. Internal logic continues to operate unless PWRDN is asserted low.
NSRT
Insert control. NSRT enables the phantom-driver outputs (PHOUTA and PHOUTB) through the
watchdog timer for insertion onto the token ring.
8
I
TTL
Static high = Inactive, phantom current removed (due to watchdog timer)
Static low = Inactive, phantom current removed (due to watchdog timer)
Falling edge = Active, current output on PHOUTA and PHOUTB
PHOUTA
PHOUTB
23
O
21
O
N
N
Phantom-driver outputs A and B. PHOUTA and PHOUTB are the outputs that cause insertion
onto the token ring. PHOUTA and PHOUTB should be connected to the center tap of the transmit
transformer secondary winding for phantom-drive generation.
PWRDN
Power-down control
H = Normal operation. PWRDN is required to be tied to VCC with an external pullup resistor
16
I
TTL
of 4.7 kΩ.
L = TI380C60A is placed into a power-down state. All TTL outputs are driven to the
high-impedance state.
PXTAL
Token-ring reference-clock output. For 16-Mbps operations, PXTAL is a 32-MHz clock; and for
1
O
TTL _{4-Mbps operations, PXTAL is an 8-MHz clock.}
OSC32
48
O
TTL
Oscillator output. OSC32 provides a 32-MHz clock output and can be used to drive OSCIN of a
TI380C2x.
Repeat-mode enable
REPT
15
I
TTL
L = Repeat mode selected. The received and sampled data present on RCVR is also driven
out on the XMT+ / XMT– pair. This function is overridden if WRAP is asserted low.
H = TI380C60A operates normally. (See Note 1)
† _{I = input, O = output, E = provides external-component connection to the internal circuitry for tuning}
‡ _{TTL = TTL signal, N = non-TTL signal, D = differential drive or data}
NOTE 1: Pin has an internal pullup device to maintain a high-voltage level when left unconnected (no etch).
Ethernet is a trademark of Xerox Corporation.
2
• POST OFFICE BOX 1443 HOUSTON, TEXAS 77251–1443