SY10E337
3-BIT SCANNABLE
REGISTERED BUS
TRANSCEIVER
SY100E337
Micrel, Inc.
SY10E337
SY100E337
FEATURES
DESCRIPTION
■ 1500ps max. clock to bus (data transmit)
■ 1000ps max. clock to Q (data receive)
■ Extended 100E VEE range of –4.2V to –5.5V
■ 25Ω cutoff bus outputs
The SY10/100E337 are 3-bit registered bus transceivers
with scan designed for use in new, high- performance ECL
systems. The bus outputs (BUS0–BUS2) are designed to
drive a 25Ω bus; the receive outputs (Q0–Q2) are designed
for 50Ω. The bus outputs feature a normal logic HIGH level
(VOH) and a cutoff LOW level of –2.0V and the output
emitter-follower is “off”, presenting a high impedance to the
bus. The bus outputs also feature edge slow-down
capacitors.
Both drive and receive sides feature the same logic,
including a loopback path to hold data. The LOAD/HOLD
functioniscontrolledbyTransmitEnable(TEN)andReceive
Enable (REN) on the transmit and receive sides,
respectively, with a HIGH selecting LOAD. The
implementation of the E337 Receive Enable differs from
that of the E336.
■ 50Ω receiver outputs
■ Scannable implementation of E336
■ Synchronous and asynchronous bus enables
■ Non-inverting data path
■ Bus outputs feature internal edge slow-down
capacitors
■ Additional package ground pins
■ Fully compatible with industry standard 10KH,
100K ECL levels
■ Internal 75KΩ input pulldown resistors
■ Fully compatible with Motorola MC10E/100E337
■ Available in 28-pin PLCC package
A synchronous bus enable (SBUSEN) is provided for
normal, non-scan operation. The asynchronous bus disable
(ABUSDIS) disables the bus for scan mode.
The SYNCEN input allows either synchronous or
asynchronous re-enabling after disabling with ABUSDIS.
An alternative use is asynchronous-only operation with
ABUSDIS, in which case SYNCEN is tied LOW. SYNCEN
is implemented as an overriding SET control to the enable
flip-flop.
Scan mode is selected by a logic HIGH at the SCAN
input. Scan input data is shifted in through S-IN, and output
data appears at the Q2 output.
All registers are clocked on the rising edge of CLK.
Additional lead-frame grounding is provided through the
ground pins (GND) which should be connected to 0V. The
GND pins are not electrically connected to the chip.
PIN NAMES
Pin
Function
Data Inputs A
A0–A2
B0–B2
Data Inputs B
S-IN
Serial (Scan) Data Input
LOAD/HOLD Controls
Scan Control
TEN, REN
SCAN
ABUSDIS
SBUSEN
SYNCEN
CLK
Asynchronous Bus Disable
Synchronous Bus Enable
Synchronous Enable Control
Clock
BUS0–BUS2
Q0–Q2
25Ω Cutoff BUS Outputs
Receive Data Outputs (Q2 serves as
SCAN_OUT in scan mode)
VCCO
VCC to Output
Rev.: F
Amendment: /0
M9999-032206
hbwhelp@micrel.com or (408) 955-1690
1
Issue Date: March 2006