UCC5646, UCC5647
27-LINE 3 V - 5 V LVD TERMINATOR
FOR WIDE ULTRA2, ULTRA3, ULTRA160 AND ULTRA320
SLUS386B FEBRUARY 2000 REVISED APRIL 2001
1
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
D
SCSI SPI-2, SPI-3, SPI-4,
Ultra160, Ultra320 Compliance
D
Smallest Footprint
D
Lowest Channel
Capacitance, 2 pF
D
Less than 0.5-pF Capacitance
Differential Between Pairs
D
2.7 V to 5.25 V Operation
D
Differential Failsafe Bias
D
64-Pin Low Profile QFP
description
The UCC5646 is a twenty-seven line active terminator for low-voltage-differential (LVD) SCSI networks. This
LVD SCSI-only design allows the user to reach peak bus performance, while reducing system cost. The device
is designed as an active Y-terminator to improve the frequency response of the LVD SCSI Bus. Designed with
a 2-pF (typical) channel capacitance, the UCC5646 allows for minimal bus loading for a maximum number of
peripherals. With the UCC5646, the designer is able to comply with the Ultra2, Ultra3, Ultra160 and Ultra320
specifications. The UCC5646 also provides a much-needed system migration path for the ever improving SCSI
system standards.
This device is available in the 64-pin low-profile QFP package for ease of layout use.
Single-ended (SE) and high-voltage differential (HVD) SCSI drivers are not supported.
AVAILABLE OPTIONS
DISCONNECT
PACKAGED DEVICES
TA
DISCONNECT
STATUS
LOW PROFILE QFP
(PM)
0
C to 70
C
REGULAR
UCC5646PM
0
C to 70
C
REVERSE
UCC5647PM
The PM package is available taped and reeled. Add TR suffix to
device type (e.g. UCC5646PMTR) to order quantities of 1000
devices per reel.
Copyright
2001, Texas Instruments Incorporated
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
17 18 19
{
DISCNCT1
{
DISCNCT2
L21
L21+
L20
L20+
L19
L19+
DIFSENS
DIFFB
L18
L18+
L17
L17+
L16
L16+
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
20
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
L25
L25+
L26
L26+
L27
L27+
STRMPWR
PTRMPWR
REG
SGND
PGND
LVD
L10
L10+
L11
L11+
21 22 23 24
L22+
L6+
63 62 61 60 59
64
58
L23+
L23
L9+
L9
L8+
L8
L7+
L3
L4+
L4
L14+
L13+
L13
L1+
L1
L2+
L2
L3+
56 55 54
57
25 26 27 28 29
53 52
L12+
L6
L5+
51 50 49
30 31 32
L14
L15+
L15
L5
L7
L22
L24+
L24
L12
{
For the UCC5647, Pin 47 is DISCNCT1 and Pin 48 is DISCNCT2.
PM PACKAGE
(TOP VIEW)
UCC5646, UCC5647
27-LINE 3 V - 5 V LVD TERMINATOR
FOR WIDE ULTRA2, ULTRA3, ULTRA160 AND ULTRA320
SLUS386B FEBRUARY 2000 REVISED APRIL 2001
2
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
block diagram
48
*DISCNCT1
12
LVD
9
REG
22
L1
21
L1+
5
L27
6
L27+
+56mV
SOURCE/SINK
REGULATOR
0.6V
2.15 V
52
52
52
52
125
SE
HPD
39
125
REF
1.25V
REF 1.3V
40
DIFSENS
1.3V +/ 0.1V
DIFFB
47
*DISCNCT2
L10 L27
L1 L9
7
8
STRMPWR
PTRMPWR
10
11
SGND
PGND
*FOR THE UCC5647 PIN 47 IS DISCNCT1 AND PIN 48 IS DISCNCT2.
+
+
+
+
+56mV
+56mV
+56mV
+
+
SE
LVD
HVD
DISCNCT
OPEN
DOWN
OPEN
OPEN
MODE
ALL SWITCHES
15mA
I
SOURCE
5mA
50
A
I
SINK
200
A
absolute maximum ratings over operating free-air temperature range (unless otherwise noted)
Input voltage V
IN
(STRMPWR, PTRMPWR)
6 V
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Signal line input voltage
0 V to 5 V
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Regulator output current
0.75 A
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Storage temperature range, T
stg
55
C to 150
C
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Operating virtual junction temperature range, T
J
55
C to 150
C
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Lead temperature (soldering, 10 seconds)
300
C
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Stresses beyond those listed under "absolute maximum ratings" may cause permanent damage to the device. These are stress ratings only, and
functional operation of the device at these or any other conditions beyond those indicated under "recommended operating conditions" is not
implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
Unless otherwise indicated, voltages are reference to ground and currents are positive into and negative out of the specified terminals. Consult
Packaging Section of the Databook for thermal limitations and considerations of packages. All voltages are referenced to GND.
UCC5646, UCC5647
27-LINE 3 V - 5 V LVD TERMINATOR
FOR WIDE ULTRA2, ULTRA3, ULTRA160 AND ULTRA320
SLUS386B FEBRUARY 2000 REVISED APRIL 2001
3
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
electrical characteristics over recommended operating free-air temperature range,
xTRMPWR = 2.7 V to 5.25 V, T
A
= 0
_
C to 70
_
C, DISCNCT1 = DISCNCT2 = 0 V for UCC5646,
DISCNCT1 = DISCNCT2 = open for UCC5647, T
A
= T
J
, (unless otherwise noted)
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
xTRMPWR Supply Current Section
xTRMPWR supply current
LVD mode
65
mA
xTRMPWR supply current
Disabled terminator
500
A
1.25 V Regulator Section
1.25 V regulator
0.5 V
VCM
2.0 V,
See Note 1
1.15
1.25
1.35
V
Regulator source current
VREG = 0 V
300
240
mA
Regulator sink current
VREG = 3.0 V
240
300
mA
1.3 V (DIFSENS) Regulator Section
1.3 V regulator
5mA
IDIFSENS
50
A
1.2
1.3
1.4
V
Short-circuit source current
VDIFSENS = 0 V
5
8
15
mA
Short-circuit sinkcurrent
VDIFSENS = 2.75 V
50
200
A
Differential Termination Section (Applies to each line pair 127)
Differential bias voltage
100
125
mV
Differential impedance
100
105
110
Common-mode bias voltage
L+ and L shorted together
1.15
1.25
1.35
V
Common-mode impedance
L+ and L shorted together,
See Note 2
110
140
165
Disconnected Termination Section
Output leakage current
10
400
nA
Output capacitance
SE measurement to GND,
See Note 3
3
pF
Disconnect Control (DISCNCT1) or (DISNCNT2) and DIFFB Input Section
DISCNCT threshold voltage
0.8
1.5
2.0
V
DISCNCT input current
VDISCNCT = 0 V and 2.0 V
30
10
A
DIFFB SE to LVD threshold voltage
0.5
0.7
V
DIFFB LVD to HPD threshold voltage
1.9
2.4
V
DIFFB Input current
0 V
VDIFFB
2.75 V,
10
10
A
Low-Voltage Differential (LVD) Status Bit Section
Source current
VLOAD = 2.4 V
6
4
mA
Sink current
VLOAD = 0.4 V
2
5
mA
Thermal Shutdown Section
Thermal shutdown threshold
For increasing temperature
140
155
170
_
C
Thermal shutdown hysteresis
10
_
C
NOTE 1: VCM is applied to all L+ and L lines simultaneously.
NOTE 2:
Z
CM
+
2.0 V
*
0.5 V
I
VCM (max)
*
I
VCM (max)
, VCM(max) = 2.0 V, VCM(min) = 0.5 V
NOTE 3: Ensured by design, not production tested.
UCC5646, UCC5647
27-LINE 3 V - 5 V LVD TERMINATOR
FOR WIDE ULTRA2, ULTRA3, ULTRA160 AND ULTRA320
SLUS386B FEBRUARY 2000 REVISED APRIL 2001
4
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
pin descriptions
STRMPWR: 2.7 V to 5.25 V power supply for all circuitry except the 1.25-V regulator.
SGND: Ground reference for all circuitry except the 1.25-V regulator.
PTRMPWR: 2.7 V to 5.25 V power supply for the 1.25-V regulator.
PGND: Ground reference for the 1.25-V regulator.
REG: Output of the internal 1.25-V regulator; must be connected to a 4.7-
F bypass capacitor and a
high-frequency, low-ESR 0.01-
F capacitor to GND.
DIFSENS: Drives the SCSI bus DIFF SENSE line to 1.3 V to detect what types of devices are tied to the bus.
DIFFB: DIFF SENSE input pin. Connect through a 20-k
resistor to DIFSENS and through a 0.1-
F capacitor
to GND. Input to comparators that detect what type of drives are connected to the SCSI bus.
DISCNCT1: Disconnect one controls termination lines 1027 (control and low byte).
DISCNCT2: Disconnect two controls termination lines 19 (high byte).
LVD: TTL compatible status bit indicating when low-voltage-differential voltage is present on DIFFB.
L1 thru L27: Negative lines for the SCSI bus.
L1+ thru L27+: Positive lines for the SCSI bus.
UCC5646, UCC5647
27-LINE 3 V - 5 V LVD TERMINATOR
FOR WIDE ULTRA2, ULTRA3, ULTRA160 AND ULTRA320
SLUS386B FEBRUARY 2000 REVISED APRIL 2001
5
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
REG
STRMPWR
DISCNCT1
CONTROL AND
LOW BYTE
DIFFB
Termpower
4.7
F
7
48
40
9
39
DIFSENS
CONTROL LINES (9)
21
22
60
59
L1+
L1
L9+
L9
DATA (8)
+ PARITY LINES
14
13
37
38
L10+
L10
L18+
L18
41
42
6
5
L19+
L19
L27+
L27
47
DISCNCT2
HIGH SIDE
PTRMPWR
8
4.7
F
UCC5646
11
10
PGND
SGND
4.7
F
0.01
F
DATA (8)
+ PARITY LINES
STRMPWR
REG
DIFFB
40
39
9
7
48
DIFSENS
21
22
60
59
L1+
L1
L9+
L9
14
13
37
38
L10+
L10
L18+
L18
DISCNCT1
CONTROL AND
LOW BYTE
Termpower
41
42
6
5
L19+
L19
L27+
L27
47
DISCNCT2
HIGH SIDE
UCC5646
PTRMPWR
8
4.7
F
11
10
PGND
SGND
4.7
F
4.7
F
0.01
F
50 k
50 k
12
0.01
F
0.01
F
LVD
UDG98202
Figure 1. Typical Application Diagram
UCC5646, UCC5647
27-LINE 3 V - 5 V LVD TERMINATOR
FOR WIDE ULTRA2, ULTRA3, ULTRA160 AND ULTRA320
SLUS386B FEBRUARY 2000 REVISED APRIL 2001
6
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
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Post Office Box 655303
Dallas, Texas 75265
Copyright
2001, Texas Instruments Incorporated
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