74abtl3205 NXP Semiconductors, 74abtl3205 Datasheet - Page 2

• Manufacturer Part Number: 74abtl3205
• Description: 10-bit Btl Transceiver With Registers
• Manufacturer: NXP Semiconductors

Philips Semiconductors
FEATURES
QUICK REFERENCE DATA
ORDERING INFORMATION
52-PIN PQFP
1995 Jun 16
SYMBOL
10-bit BTL transceiver
Drives heavily loaded backplanes with equivalent load
impedances down to 10 ohms
High drive 100mA BTL open collector drivers on B-port
Allows incident wave switching in heavily loaded backplane buses
Reduced BTL voltage swing produces less noise and reduces
power consumption
Built-in precision band-gap reference provides accurate receiver
thresholds and improved noise immunity
Compatible with IEEE Futurebus+ or proprietary BTL backplanes
Controlled output ramp and multiple GND pins minimize ground
bounce
Tight output skew (0.5nsec typical)
Glitch-free power up/down operation
Low I
Supports live insertion
High density packaging
ESD protection exceeds 2000V per MIL STD 883 Method 3015
and 200V per Machine Model
10-bit BTL transceiver with registers
t
t
t
t
C
I
PLH
PHL
PLH
PHL
I
OL
CC
OB
CC
current
PACKAGES
Propagation delay
An to Bn
Propagation delay
Bn to An
Output capacitance (B0 - B8) only)
Output current (B0 - B8) only)
Supply current
TEMPERATURE RANGE
–40 C to +85 C
PARAMETER
Standby
An to Bn
Bn to An
OUTSIDE NORTH AMERICA
2
74ABTL3205 BB
DESCRIPTION
This transceiver is a 10 bit bidirectional transceiver and is intended
to provide the electrical interface to a high performance wired-OR
bus.
The B-port drivers are Low-capacitance open collectors with
controlled ramp and are designed to sink 100mA. Precision band
gap references on the B-port insure very good margins by limiting
the switching threshold to a narrow region centered at 1.55V.
The B-port interfaces to “Backplane Transceiver Logic” (See the
IEEE 1194.1 BTL standard). BTL features low power consumption
by reducing voltage swing (1V p-p, between 1V and 2V) and
reduced capacitive loading (<6pF) by placing an internal series
diode on the drivers. BTL also provides incident wave switching, a
necessity for high performance backplanes.
To support live insertion, OEB is held Low during power on/off cycles
to insure glitch free B port drivers. Proper bias for B port drivers
during live insertion is provided by the BIAS V pin when at a 5V level
while V
reverse bias the BTL driver series Schottky diode, and also bias the
B port output pins to a voltage between 1.62V and 2.1V. This bias
function is in accordance with IEEE BTL standard 1194.1. If live
insertion is not a requirement, the BIAS V pin should be tied to a
V
The LOGIC GND and BUS GND pins are isolated inside the
package to minimize noise coupling between the BTL and TTL
sides. These pins should be tied to a common ground external to the
package. The LOGIC V
internally to minimize noise and may be externally decoupled
separately or simply tied together.
This transceiver function is intended to operate in a half-duplex
mode. Low current in standby mode is obtained by powering down
unused circuitry. Likewise, transmit circuitry is powered down when
in receive mode and receive circuitry is powered down while in
transmit mode.
CC
pin.
CC
is Low. The BIAS V pin is a low current input which will
CC
NORTH AMERICA
and BUS V
74ABTL3205 BB
CC
pins are also isolated
74ABTL3205
TYPICAL
Product specification
100
3.3
3.7
3.6
3.5
18
6
1
7
DWG NUMBER
853-1802 15352
SOT379-1
UNIT
mA
mA
pF
ns
ns
ns
ns