TMS38054FNL [TI]
TMS38054 RING INTERFACE DEVICE; TMS38054环接口设备
| 型号： | TMS38054FNL |
| 厂家： | 
TEXAS INSTRUMENTS |
| 描述： | TMS38054 RING INTERFACE DEVICE |
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TMS38054
RING INTERFACE DEVICE
SPWS008C – APRIL 1991 – REVISED MAY 1997
Facilitates Connection of the TI380C25,
TI380C27, or TMS380C26 to a Token-Ring
Network
Phantom Drive for Physical Insertion Onto
Ring
16-Mbps and 4-Mbps Token-Ring Data
Rates
Compatible With Electrical Interface of
ISO/IEC IEEE Std 802.5:1992 Token-Ring
Access Method and Physical-Layer
Specifications
Integrated Receiver Frequency Equalization
Loop Back (Wrap Mode) for Self-Test
Diagnostics
Constant-Gain Phase Detector for
Unshielded Twisted Pair (UTP) Applications
On-Chip Watchdog Timer
ESD Protection Meets 1.5 kV Per
MIL-STD-883C, Method 3015
Phase-Locked Loop (PLL) for Clock
Generation and Data Signal Recovery
Advanced Low-Power Schottky Technology
Packaged in Plastic J-Leaded Chip Carrier
Independent Transmit and Receive
Channels
FN PACKAGE
(TOP VIEW)
6
5
4
3
2 1 44 43 42 41 40
SPSW
NC
GNDA2
39
7
RCVINA
38
8
VCOGAN
GNDA1
RCVINB
37
9
WRAP
36
10
11
12
13
14
15
16
17
V
DRVR
35
CCA1
FILTER
GNDA1
NC
DRVR
34
V
33
32
31
30
29
CCD
DROUTA
GNDA1
STERES
GNDA1
DROUTB
GNDRV
PHOUTB
18 19 20 21 22 23 24 25 26 27 28
NC – No internal connection
description
The TMS38054 ring interface device and its associated external passive components form a full-duplex
electricalinterfacetothetokenring. CouplingtheTMS38054withoneoftheTMS380familyofcommprocessors
forms a highly integrated token-ring LAN adapter compatible with the ISO/IEC IEEE Std 802.5:1992 token-ring
access method and physical-layer specifications.
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.
Token-Ring Network is a trademark of International Business Machines Corporation.
Copyright 1997, 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.
1
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TMS38054
RING INTERFACE DEVICE
SPWS008C – APRIL 1991 – REVISED MAY 1997
description (continued)
The TMS38054 operates at the IEEE-standard 16-Mbps and 4-Mbps data rates. The token-ring data stream
isreceivedbytheTMS38054andphasealignedusinganon-chipphase-lockedloop(PLL). Therecoveredclock
and data are passed to the TI380C2x single-chip token-ring commprocessor’s protocol-handling circuits for
serial-to-parallel conversion and data processing. On transmit, the TMS380C2x provides a differential signal
that the TMS38054 converts to analog levels for transmission on the media. A watchdog timer also is included
to provide fail-safe deinsertion from the ring in the event of a station failure. The phase-detector gain is constant
for all valid differential Manchester data that provide increased margin for unshielded twisted-pair applications.
The TMS38054 is available in a 44-lead plastic chip carrier. The TMS38054 is characterized for operation from
0°C to 70°C with case temperature maintained at or below 99°C.
Token-Ring Adapter
Transmit
Attached
System
Bus
TMS380C2x
Memory
TMS38054
To Network
Receive
Figure 1. Token-Ring LAN Application Diagram
2
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TMS38054
RING INTERFACE DEVICE
SPWS008C – APRIL 1991 – REVISED MAY 1997
Terminal Functions
TERMINAL
†
‡
DESCRIPTION
I/O/E
TYPE
NAME
NO.
DROUTA
DROUTB
32
31
Driver outputs A and B. DROUTA and DROUTB are the differential driver outputs to the token
ring via isolation transformers.
O
I
D
D
DRVR
DRVR
35
34
Differential driver data inputs. DRVR and DRVR are the differential inputs that receive the
’380C2x transmit data.
Output-enable control. ENABLE is the TTL input used to enable a board-test mode.
High = TMS38054 operates normally
ENABLE
5
I
T
Low
=
All TTL outputs and phantom drive outputs are driven to the high-impedance state.
DROUTA and DROUTB are not affected.
EQUALA
EQUALB
44
43
Equalization/gainpoints A and B. EQUALA and EQUALB are connections that allow frequency
tuning of the equalization circuit.
E
E
N
N
Charge pump output/filter buffer input. FILTER allows connection of external components for
the PLL filter.
FILTER
12
Frequency acquisition control. FRAQ determines the use of frequency or phase-acquisition
mode.
FRAQ
22
I
T
High = Wide range. Frequency centering to XTAL reference.
Low
= Narrow range. Phase locked onto the incoming data (RCVINA and RCVINB).
10, 13,
15, 17
§¶
§¶
GNDA1
Ground reference for VCO and filter input
GNDA2
39, 40
1, 6
Ground reference for receiver circuits
Ground reference for input and output buffers
Ground reference for digital circuits
Ground reference for driver output circuits
Not internally connected
§¶
GNDB
GNDD
GNDRV
§
20, 28
30
§
§
NC
8, 14
Energy-detect capacitor. NRGCAP allows connection to an external capacitor for sensing
received-data transitions (energy).
NRGCAP
NSRT
19
24
E
I
N
T
Phantom-driver control. NSRT enables PHOUTA and PHOUTB through the watchdog timer for
insertion onto the token ring.
Static high
Static low
=
=
Inactive, phantom current removed (due to watchdog timer)
Inactive, phantom current removed (due to watchdog timer)
Falling edge = Active, current output on PHOUTA and PHOUTB
PHOUTA
PHOUTB
27
29
O
N
Phantom-driver outputs A and B. PHOUTA and PHOUTB cause insertion onto the token ring.
Recovered clock. RCLK is the clock recovered from the token-ring received data. For 16-Mbps
operation, RCLK is a 32-MHz clock. For 4-Mbps operation, RCLK is an 8-MHz clock.
RCLK
3
O
E
I
T
N
D
T
RCVHYS
42
Receiver hysteresis resistor. RCVHYS allows setting of the receiver (hysteresis) threshold.
RCVINA
RCVINB
38
37
Receiver inputs A and B. RCVINA and RCVINB receive the token-ring data via isolation
transformers.
RCVR
2
O
Recovered data. RCVR contains the data recovered from the token ring.
Ready. REDY to the ’380C2x provides an indication that sufficient time has elapsed since the
last transition of FRAQ for the PLL to achieve lock as monitored by the energy-detect capacitor.
18
O
T
REDY
High = Received data not valid
Low
= Received data valid
†
‡
§
¶
I = input, O = output, E = provides external component connection to the internal circuitry for tuning
T = TTL signal, N = non-TTL signal, D = differential drive or data
These terminals should be connected to a single power or ground plane as appropriate.
GNDA1, GNDA2, and GNDB are internally connected together.
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POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TMS38054
RING INTERFACE DEVICE
SPWS008C – APRIL 1991 – REVISED MAY 1997
Terminal Functions (Continued)
TERMINAL
†
‡
DESCRIPTION
I/O/E
TYPE
NAME
NO.
Speed switch. SPSW specifies the token-ring data rate.
High = 4-Mbps data rate
SPSW
7
I
T
Low
= 16-Mbps data rate
Static timing error resistor. STERES allows connection to an external resistor for adjusting the
static-timing error.
STERES
16
E
N
§
§
V
V
11
41
Positive supply voltage for VCO and filter input
CCA1
Positive supply voltage for receiver circuits
CCA2
§
V
4
Positive supply voltage for input and output buffers
CCB
CCD
§
V
21, 33
9
Positive supply voltage for digital circuits (5 V)
VCOGAN
E
E
N
N
VCO gain resistor. VCOGAN allows connection to an external resistor for setting the VCO gain.
Watchdog timer capacitor. WDTCAP allows connection to an external capacitor, which sets the
watchdog-timeout period.
WDTCAP
25
Phantom-wire-fault. WFLT provides an indication of the presence of a short circuit or open on
PHOUTA or PHOUTB.
26
O
T
WFLT
High = No fault
Low
= Open or short
Internal-wrap mode control. WRAP allows the TMS38054 to be placed in the loopback-wrap
mode for adapter self test.
36
23
I
I
T
T
WRAP
XTAL
High = Normal ring operation
Low
= Transmit data drives the receive data.
Crystal-oscillator input. XTAL (normally externally gated by FRAQ) is used to synchronize the
PLL. XTAL is 32 MHz for 16-Mbps ring, and 8 MHz for 4-Mbps ring.
†
‡
§
I = input, O = output, E = provides external component connection to the internal circuitry for tuning
T = TTL signal, N = non-TTL signal, D = differential drive or data
These terminals should be connected to a single power or ground plane as appropriate.
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POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TMS38054
RING INTERFACE DEVICE
SPWS008C – APRIL 1991 – REVISED MAY 1997
architecture
The major blocks of the TMS38054 include the receiver, data latch, transmitter, wrap, voltage regulator, energy
detect, phase-locked loop, watchdog timer, and phantom driver and wire-fault detect (see functional block
diagram). The functionality of each block is described in the following sections.
functional block diagram
25
WDTCAP
27
PHOUTA
PHOUTB
WFLT
Phantom Driver and
Wire-Fault Detect
24
36
NSRT
Watchdog Timer
29
26
WRAP
32
31
35
34
DRVR
DRVR
DROUTA
DROUTB
Transmitter
Data Latch
Wrap
38
37
RCVINA
RCVINB
2
3
Receiver
RCVR
RCLK
44
43
42
EQUALA
EQUALB
RCVHYS
7
SPSW
23
12
9
XTAL
FILTER
Phase-Locked
Loop/Clock
Recovery
Voltage
Regulator
3.9 V
VCOGAN
STERES
FRAQ
16
22
18
19
REDY
Energy Detect
NRGCAP
ENABLE
5
receiver
The receiver circuit reads incoming data from the ring and performs five other functions:
Provides dc bias for the differential input
Provides clamping of large signal swings
Provides gain and equalization
Provides definition of thresholds
Provides hysteresis for data detection
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POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TMS38054
RING INTERFACE DEVICE
SPWS008C – APRIL 1991 – REVISED MAY 1997
receiver (continued)
Gain as a function of frequency is set by the equalizer impedance. Equalization characteristics are determined
by the external equalization circuit across EQUALA and EQUALB. Equalization is effective at low-signal
amplitudes. At larger-signal levels, nonlinear effects reduce the effective equalization. The signal level at which
saturation occurs is determined by the impedance between EQUALA and EQUALB. The circuit is suitable for
differential Manchester-encoded data at 16 Mbps or 4 Mbps.
data latch
The output of the receiver drives two internal circuits: the data latch and the phase detector. The latch samples
the internal receiver output signal on the rising edge of the internal recovered clock. Data (RCVR) is therefore
stable and can be sampled at the rising edge of RCLK. The timing of this edge is set by the phase detector and
other loop components so that the received signal is sampled at the optimum time for error-free data recovery.
Both the sampled data and the recovered clock signal are buffered and sent to the ’380C2x token-ring
commprocessor as the RCVR and RCLK signals to provide decoding of the differential Manchester data.
Static-timing error is defined as the amount of error that the rising edge of the recovered clock has from the
midpoint of the data signal into the data latch. An error of zero is optimum sampling, as this places the rising
edge of the sampling clock in the middle of the data pulse. A positive offset represents early sampling.
transmitter
The transmit driver provides differential current drive at a suitable level for driving the data onto the ring. Both
outputs (DROUTA and DROUTB) are open collector and intended to drive a center-tapped transformer with the
centertapconnectedtoV .Theoutputstagecontrolsafixedcurrentbetweenthetwooutputsunderthecontrol
CC
of the driver data input (DRVR and DRVR).
DRVR and DRVR drive a differential transmit circuit that enhances the symmetry of the current switching on
DROUTA and DROUTB. The DRVR and DRVR inputs are not retimed within the TMS38054. Consequently, low
skew in the input is important in order to avoid degrading the transmitted output waveform. The transmitter-drive
outputs are not affected by ENABLE. When DRVR is high and DRVR is low, the output current is directed to
DROUTA and, when reversed, to DROUTB.
wrap
The wrap function provides an internal signal path used for system self-test diagnostics. When WRAP is taken
low, the transmitter outputs are disabled and the receiver inputs are ignored. An alternate path is provided from
the transmitter output circuitry to the receiver input circuitry through the wrap circuit. This wrap path to RCVR
inverts the transmitted signal. In the internal-wrap mode, attenuation is checked by observing the signal
amplitude at EQUALA and EQUALB. Equalization is active at this signal level although the signal does not
exhibit the high-frequency attenuation effects for which equalization is intended to compensate.
phantom driver and wire-fault detector
The phantom-drive circuit under control of NSRT generates a dc signal on both of the two drive outputs,
PHOUTA and PHOUTB. To maintain the dc signal, NSRT must provide a positive (low-to-high) clock edge once
every 20 ms. An internal watchdog timer (oneshot) is designed so that the PHOUTA and PHOUTB dc signals
are removed if NSRT fails to have the required transitions. The PHOUTA and PHOUTB signals are sent over
the transmit-signal pair to the trunk-coupling unit (TCU) to request that the station be inserted into the ring. The
signal current is detected by the TCU, causing the external-wrap path from the transmitter outputs back to the
receiver inputs to be broken. A connection is established from the ring to the receiver inputs and from the
transmitter outputs to the ring. The phantom-drive outputs are short-circuit protected; they detect a short circuit
from either output to ground or when there is an abnormally low load current at either output corresponding to
an open circuit in the signal or TCU wiring. Either type of fault results in WFLT being driven low. The logic state
of WFLT is high when NSRT is high. All three outputs, PHOUTA, PHOUTB, and WFLT, are in the
high-impedance state when ENABLE is low.
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POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TMS38054
RING INTERFACE DEVICE
SPWS008C – APRIL 1991 – REVISED MAY 1997
watchdog timer
The watchdog timer provides protection against a failed adapter remaining on the ring. NSRT must be toggled
low or the watchdog timer turns off the phantom drive. The period of the watchdog timer is determined by the
value of the external capacitor connected to WDTCAP. The capacitor is chosen to give a period of 21 ms
minimum and 50 ms maximum. This assures compatibility with a system that toggles NSRT at a rate faster than
once every 20 ms and assures deinsertion from the ring within 50 ms of the last NSRT high-to-low transition.
The duty cycle of NSRT is not critical. Phantom drive is turned on following a falling NSRT edge. Deinsertion
occurs if NSRT is left high or low or if the internal-wrap mode is selected from WRAP. The following describes
the operation of the watchdog timer and indicates the priorities of the control signals:
WRAP is low (internal mode selected):
–
Phantom drive is off. Operation of the watchdog timer is not defined but can continue, and if the timer
has not expired, taking WRAP high can result in the phantom drive being turned on.
WRAP is high:
–
–
–
–
If the timing capacitor is connected and NSRT goes from high to low, the timing capacitor is charged or
recharged to a defined level. Phantom drive is on and discharging of the timing capacitor continues.
If the timing capacitor is connected and NSRT goes from low to high, there is no effect on the watchdog
timer and the discharging of the timing capacitor continues.
If the timing capacitor is connected and the capacitor discharges to a defined level, the phantom drive is
turned off regardless of the state of WRAP.
If the timing capacitor is not connected and the timing capacitor pin is held to V
+ 0.5 V, the phantom
CC
drive is controlled directly by NSRT. This serves to disable the watchdog-timer function.
voltage regulator
The internal voltage regulator is used to make the performance of the TMS38054 less dependent on the supply
voltage. The regulator consists of a band-gap reference scaled up to a nominal 3.9 V with a temperature
coefficient designed to compensate for coefficients in circuits referenced to the voltage regulator.
PLL/clock recovery
The TMS38054 contains a PLL for recovering a data clock from the received bit stream. The elements of PLL
are: phase and frequency detectors, a charge pump, an external filter (connected to FILTER), a filter buffer, a
voltage-to-current converter, and a voltage-controlled oscillator (VCO). There are three pins on the TMS38054
that allow connection to external components and tuning of the characteristics of the PLL. These pins are
FILTER, STERES, and VCOGAN. Figure 2 illustrates these blocks. The following paragraphs describe the PLL
elements.
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POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TMS38054
RING INTERFACE DEVICE
SPWS008C – APRIL 1991 – REVISED MAY 1997
From Receiver
Recovered Clock
Multiplexer
FILTER
+
STERES
SPSW
Filter
Buffer
UP
XTAL
Frequency
Detector
Charge
Pump
DOWN
–
Divide by 4
FRAQ
Voltage-to-Current
Converter (V/I)
VCO
Phase
Detector
VCOGAN
To Energy-Detect Block
Figure 2. Phase-Locked-Loop Block Diagram
phase and frequency detectors
The phase- and frequency-detector blocks generate control signals suitable for controlling the charge pump.
The frequency detector is used to bring the frequency of the VCO close to the frequency of XTAL. The phase
detector is used to provide precise phase alignment of the recovered clock to the incoming data. The circuit is
not capable of locking the PLL in cases in which the VCO frequency and incoming data frequency differ
substantially, hence, the need for frequency centering before phase alignment to incoming data occurs.
The phase detector compares the phase of the received data and the recovered clock, and accordingly
generates the charge pump control signals, UP and DOWN. The width of the UP pulse is determined by the
phase alignment of the received data and the recovered clock. Each UP pulse is followed by a DOWN pulse
of constant width. Phase-detector UP-DOWN sequences are initiated at a 16-MHz rate for all valid differential
Manchester data patterns. This rate can drop momentarily during code violations or delimiters, but such
deviations are of short duration and the gain of the phase detector can be considered constant.
A multiplexer selects the required detection mode during insertion onto the ring. The frequency-detection mode
is selected by taking FRAQ high and the phase-detection mode is selected by taking FRAQ low. The phase or
frequency detectors supply the necessary charge (or UP) and discharge (or DOWN) control signals to the
charge pump.
charge pump
The charge pump supplies charge to and removes charge from the external filter components.The output of
either the phase detector or frequency detector drives the charge pump as selected by FRAQ. The charge pump
has two internal inputs, so there are four possible states of the charge pump:
Pump UP – current into the filter, increasing the voltage
Pump DOWN – current out of the filter, reducing the voltage
No pump – in the high-impedance state, holding the voltage on the filter
Pump UP and pump DOWN – both currents on (not allowed by the detector logic)
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POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TMS38054
RING INTERFACE DEVICE
SPWS008C – APRIL 1991 – REVISED MAY 1997
charge pump (continued)
The pump UP and pump DOWN currents are approximately equal; the net charge supplied by the charge pump
in a given time depends primarily on the relative duration and frequency of UP and DOWN controls from the
phase and frequency detectors. If the net current output is positive, the voltage at FILTER rises causing an
increase in the VCO clock frequency. If the net output is negative, the FILTER voltage falls, slowing the
VCO clock.
The charge-pump block has two constant-current circuits operating continuously, one for pump UP and one for
pump DOWN. They are designed for stability under all operating conditions. The UP current is fixed and directly
affectsthemagnitudeoftheloopgainandthebandwidthanddampingfactoroftheloop. Anydifferencebetween
the UP and DOWN currents creates an offset in the loop, which introduces a static-timing error. Provision for
an external resistor at STERES is included to allow slight variation in the DOWN current and allows the
static-timing error of the loop to be adjusted to compensate for error introduced by the charge pump and other
elements of the PLL. This resistor is not required for normal operation of the TMS38054, but provisions should
be made to accommodate this resistor in future applications.
external filter
The external filter consists of passive external components connected from FILTER to ground. A system
diagram for the PLL circuit is shown in Figure 3. The phase-detector/charge-pump gain, G , is given in the
d
electrical specifications as 16 Mbps. This value is true for any valid differential Manchester data pattern. The
result is in µA/ns, which can be converted to A/rad by using equation 1. The value, in A/rad, is the same at both
16 Mbps and 4 Mbps.
The VCO gain, G , is given in the electrical specifications at 16 Mbps. This value is in MHz/V, which can be
o
converted to rad/volt by using equation 1. The value at 4 Mbps is one-fourth this value because of the ×4 divider
on the VCO output at 4 Mbps.
+
Phase
Detect
Charge
Pump
External
Filter
Filter
Buffer
Recovered
Clock
VCO
–
Figure 3. Analytical PLL Diagram
A typical external filter circuit is shown in Figure 4. Capacitor C5 limits the filter-buffer ripple but should be
chosen to be as small as possible to reduce PLL overshoot. The resistor (R5) sets the effective bandwidth of
the PLL closed loop, and capacitor C4 sets the damping factor. The filter buffer is an amplifier with bandwidth
of 3–5 MHz.
+
Phase
Detect
Recovered
Clock
KO
S
K
B(S)
d
–
External
Filter
R5
C4
C5
GND
GND
Figure 4. Analytical PLL Model
9
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TMS38054
RING INTERFACE DEVICE
SPWS008C – APRIL 1991 – REVISED MAY 1997
external filter (continued)
The simplified equations for the PLL are:
VCO gain
6
(1)
(
)
(
)( )
F
rad/(s • v)
Ko
Go 10
2
Phase-detector gain
9
(
3)(
)(
)
Gd 10 31.25 10
A/rad
Kd
2
PLL-noise-equivalent bandwidth
(
)
(
)
Ko Kd R5 in ohms
Hz
BL
4
Where:
G
G
F
= the VCO gain measured in MHz/V
o
d
= phase-detector gain measured in µA/ns
= the frequency divider factor; i.e., F = 1 for 16-Mbps operation
F = 0.25 for 4-Mbps operation
These equations are only a guide and the actual bandwidth and PLL-damping characteristics should be
obtained through correlation and modeling on specific hardware implementations that take into effect all circuit
card parasitics. Both 16-Mbps and 4-Mbps ring operation can be achieved by suitable selection of glue
components at each frequency. More information on PLL characteristics are found in:
Gardner, Floyd, Phase Lock Techniques, John Wiley & Sons, 1979.
Token Ring Access Method and Physical Layer Specification, ANSI/IEEE/ISO/IEC Standard 802.5:1992.
Gardner, Floyd, “Charge-Pump Phase-Locked Loops”, IEEE Transaction Communications, Vol. COM–28,
pp. 1849–1858, Nov. 1980.
filter buffer and voltage-to-current converter (V/I)
The filter-buffer amplifier is a unity-gain amplifier used to buffer the voltage present at FILTER with minimal
leakage current. The output of the filter buffer drives a voltage-current (V/I) converter that produces equal
currents, proportional to the filter voltage, for use in the VCO. The current level or constant of proportionality
is set by the external resistor connected to ground connected at VCOGAN. This resistor sets the VCO gain,
which is critical to loop gain and damping. The filter voltage range over which the current level tracks the voltage
determines the pull-in range of the VCO.
VCO
The VCO is an emitter-coupled astable multivibrator. The frequency is set by internal circuit parameters, the
currents from the filter buffer, and an internal VCO timing capacitor. Symmetrical circuit design helps ensure
symmetry of the VCO output, which has a nominal frequency of 32 MHz. The VCO output is buffered and sent
to the divider (for 4-Mbps operation) and multiplexer circuit.
divider and multiplexer
The multiplexer selects the source of the recovered clock, which can be either the direct output of the VCO
(nominally a 32-MHz signal) or the divided version of the VCO output (nominally an 8-MHz signal) for 16- or
4-Mbps operation. The output clock of the VCO is fed to a divide-by-4 circuit and to a multiplexer. The divider
is enabled when SPSW is high. The recovered clock is passed to frequency and phase detectors, the clock of
the data latch, and is buffered at RCLK and passed on to the ’380C2x commprocessor for processing of the
received data.
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POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TMS38054
RING INTERFACE DEVICE
SPWS008C – APRIL 1991 – REVISED MAY 1997
energy detect
The energy-detect circuit provides a timing delay on REDY. When FRAQ changes state, it indicates to the
energy-detect circuit that a change of lock mode has occurred and that time must be allowed before data
recovered by the TMS38054 can be considered valid. The energy-detect-timing capacitor is discharged shortly
after a low or high going transition of FRAQ, which results in the REDY signal being deasserted.
The time taken for the TMS38054 to acquire phase lock depends on the transition density of the incoming data,
so the delay of the energy-detect circuit also changes. Each rising transition of data results in a current pulse
of fixed duration being injected into the energy-detect-timing capacitor. The charge time of the capacitor is
dependentonincoming-data-transitiondensityandREDYisreassertedafterthecapacitorreachesaninternally
set threshold voltage.
A small discharge current is always present on the energy-detect-timing capacitor. When the
incoming-data-transition density falls below a certain threshold, the current pulses may not be sufficient to
overcome this discharge current and REDY may not be asserted.
test mode
The TMS38054 features a test mode for board-level testing with the components in the circuits. This facilitates
testing by bed-of-nails testers. This test mode is enabled by pulling ENABLE to a low level. DROUTA and
DROUTB are not affected by this function. When ENABLE is high, the TMS38054 operates normally. When
ENABLE is low, the circuit continues to operate except that PHOUTA, PHOUTB, RCVR, WFLT, and RCLK are
driven to the high-impedance state and REDY is driven high.
external passive circuitry
Figure 5 shows an arrangement of external components for a typical 16-Mbps or 4-Mbps token-ring interface.
The selection of component values is dependent on the objective of the design. The design needs to take into
account the importance of layout and component selection (values and tolerances).
The ISU1 and ISU2 blocks represent transformers that couple data from the TMS38054 to the ring. They also
represent protection circuitry against large voltage excursions. Information on ISU1 and ISU2 connections can
be found in the TMS38054 Second-Generation Ring Interface Design Note (revision C). To obtain this design
note, contact the TMS380 Technical Support Line at NETWORKS@ti.com.
11
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TMS38054
RING INTERFACE DEVICE
SPWS008C – APRIL 1991 – REVISED MAY 1997
Table 1. Typical Components for Figure 5
SYMBOL(S)
FUNCTION
Equalizer capacitor
C1
C3
Energy-detect capacitor
C4
PLL-filter capacitor
C5
PLL-filter capacitor
C10, C11
C12
Phantom-drive isolation capacitor
Watchdog-timer capacitor
Phantom surge-suppression diodes
Driver surge-suppression zener diode
Equalizer resistor
D1–D4
D13
R1
R2
Equalizer resistor
R3
VCO gain resistor
R4
Receiver-hysteresis resistor
PLL-filter resistor
R5
R14, R15
R17
Phantom-drive resistor
Static-timing-error resistor
Isolation/shaping unit (see previous page)
Isolation/shaping unit (see previous page)
ISU 1
ISU 2
12
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TMS38054
RING INTERFACE DEVICE
SPWS008C – APRIL 1991 – REVISED MAY 1997
5 V
TMS38054
32
31
34
18
5
24
26
36
35
3
†
†
OUT
OUT
DROUTA
DROUTB
DRVR
REDY
ENABLE
NSRT
WFLT
WRAP
DRVR
RCLK
RCVR
FRAQ
XTAL
ISU2
D13
5 V
D1
R14
27
2
PHOUTA
PHOUTB
22
23
7
D2
C10
5 V
SPSW
FILTER
D3
R15
12
29
C11
D4
C4
C5
R5
5 V
R3
9
38
37
†
†
VCOGAN
RCVINA
RCVINB
IN
C12
ISU1
5 V
25
42
WDTCAP
RCVHYS
NRGCAP
IN
R4
C3
R1
44
43
EQUALA
EQUALB
19
16
C1
R2
R17
STERES
†
Refer to the TMS38054 Second-Generation Ring Interface Design Note (revision C) for further information.
Figure 5. Typical Token-Ring Interface Circuit for 16 Mbps or 4 Mbps
‡
absolute maximum ratings (unless otherwise noted)
Supply voltage range, V
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.5 V to 7 V
CC
Input voltage range, V (see Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.5 V to 7 V
I
Output voltage range: Driver outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.5 V to 8 V
All other outputs (see Note 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.5 V to 7 V
Power dissipation (see Note 3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.25 W
Storage temperature range, T
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –10°C to 150°C
stg
‡
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.
NOTES: 1. Inputs may be taken to more negative voltages if the current is limited to 20 mA.
2. These outputs may not be taken more than 0.5 V above the V
3. Maximum power dissipation per package
pins.
CC
13
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TMS38054
RING INTERFACE DEVICE
SPWS008C – APRIL 1991 – REVISED MAY 1997
†
recommended operating conditions
MIN NOM
MAX
UNIT
V
V
CC
V
IH
V
IL
Supply voltage
4.75
2
5
5.25
High-level input voltage
Low-level input voltage
WRAP, ENABLE, FRAQ, XTAL, NSRT, SPSW
WRAP, ENABLE, FRAQ, XTAL, NSRT, SPSW
V
0.7
V
Receiver input bias voltage (see Note 4)
High-level output current
Low-level output current
Operating case temperature
V
SB
–1
V
+1
V
SB
I
I
RCVR, RCLK, WFLT, REDY
REDY, RCVR, WFLT, RCLK
–0.1
1
mA
mA
°C
OH
OL
T
0
99
C
†
Recommended operating conditions indicate the conditions that must be met to ensure that the device functions as intended and meets the
detailed electrical specifications. Unless otherwise noted, all electrical specifications apply for all recommended operating conditions. Voltages
are measured with respect to the device ground pins. Currents into the device are considered to be positive.
NOTE 4:
V
istheself-biasvoltageoftheinputpairRCVINAandRCVINB. ItisdefinedasV
= (V + V
)/2(whereV is the self-bias
SB
voltage of RCVINA; V
SB
SBA SBB
SBA
is the self-bias voltage of RCVINB). The self-bias voltage of both pins is approximately V /2.
CC
SBB
electrical characteristics over recommended range of supply voltage (unless otherwise noted)
TTL input
TEST
CONDITIONS
PARAMETER
WRAP, ENABLE, FRAQ, XTAL, NSRT, SPSW
MIN
MAX
UNIT
I
I
High-level input current
Low-level input current
V = 2.7 V
20
µA
IH
I
WRAP, ENABLE, FRAQ, XTAL, NSRT, SPSW
V = 0.4 V
I
–0.4
mA
IL
Input current
at maximum input voltage
I
I
WRAP, ENABLE, FRAQ, XTAL, NSRT, SPSW
V = 7 V
I
100
µA
WRAP, ENABLE, FRAQ, XTAL, NSRT, SPSW,
DRVR, DRVR
V
IK
Input clamp voltage
I = –12 mA
I
–1.5
V
TTL output (RCVR, RCLK, REDY, and WFLT)
TEST
CONDITIONS
PARAMETER
MIN
MAX
UNIT
V
V
High-level output voltage
I
I
= –0.1 mA
= 1 mA
2.4
V
V
OH
OH
Low-level output voltage
0.45
±100
±100
OL
OL
I
Off-state output current with high-level voltage applied
Off-state output current with low-level voltage applied
V
= 2.7 V
µA
µA
OZH
OZL
O
O
I
V
= 0.4 V
14
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TMS38054
RING INTERFACE DEVICE
SPWS008C – APRIL 1991 – REVISED MAY 1997
electrical characteristics over recommended range of supply voltage (unless otherwise noted)
(continued)
receiver input (RCVINA and RCVINB)
PARAMETER
TEST CONDITIONS
MIN
MAX
UNIT
mV
Rising input threshold voltage, V
V
V
V
= V , R4 = 2.49 kΩ, R = 330 Ω, See Notes 4, 5, and 6
35
T+
IC
IC
IC
SB tst
†
†
Falling input threshold voltage, V
T–
= V , R4 = 2.49 kΩ, R = 330 Ω, See Notes 4, 5, and 6
SB tst
–35
mV
Asymmetry threshold voltage, (V + V
T+
)
= V , R4 = 2.49 kΩ, R = 330 Ω, See Notes 4, 5, and 6
SB tst
–20
20
30
mV
T–
Rising input common-mode rejection
†
R
R
= 330 Ω, R4 = 2.49 kΩ, See Notes 4, 5, and 6
= 330 Ω, R4 = 2.49 kΩ, See Notes 4, 5, and 6
–30
–30
mV
mV
tst
tst
[V (@V
T+
+ 0.5 V) – V (@V
T+
– 0.5 V)]
– 0.5 V)]
SB
SB
Falling input common-mode rejection
[V (@V + 0.5 V) – V (@V
†
30
T+ T+
SB
SB
R
R
= 330 Ω, Both inputs at V , See Note 4
SB
±25
tst
tst
= 330 Ω, Input under test at V
SB
+ 1.0 V,
300
700
Other input at V
– 1 V, See Note 4
Receiver input current
µA
SB
R
= 330 Ω, Input under test at V
SB
– 1.0 V,
tst
Other input at V
–300
–700
+ 1.V, See Note 4
SB
Equalizer bias current
(EQUALA and EQUALB)
RCVINA and RCVINB open, EQUALA and EQUALB at 3 V
1.125 1.875
mA
†
The algebraic convention, where the more negative (less positive) limit is designated as a minimum, is used in this data sheet for threshold
voltages only.
NOTES: 4.
V
istheself-biasvoltageoftheinputpairRCVINAandRCVINB.ItisdefinedasV =(V
is the self-bias voltage of RCVINB). The self-bias voltage of both pins is approximately V /2.
SBB CC
is a resistor connected between pins 43 and 44; it replaces R1, R2, and C1 (see Figure 5).
+V
)/2(whereV istheself-bias
SB
voltage of RCVINA; V
SB
SBA SBB
SBA
5.
6.
R
tst
IC
V
is the common-mode voltage applied to RCVINA and RCVINB.
transmitter
PARAMETER
TEST CONDITIONS
MIN
MAX
35
UNIT
mA
µA
Output current, on
DROUTA, DROUTB
DROUTA, DROUTB
V
V
= V
CC
,
See Note 7
See Note 7
20
O
Output current, off
= 8 V,
100
100
700
–700
O
Output current, off
DROUTA, DROUTB WRAP = V
,
V
O
= 8 V
µA
IL
I
I
High-level input current
Low-level input current
Input under test at 2.7 V, Other input at 0.4 V
Input under test at 0.4 V, Other input at 2.7 V
100
µA
DRVR, DRVR
DRVR, DRVR
IH
–100
µA
IL
NOTE 7: Output not under test is loaded with 75 Ω to V
.
CC
phantom driver (PHOUTA and PHOUTB)
PARAMETER
TEST CONDITIONS
MIN
4.1
3.8
–4
MAX
UNIT
I
I
= –1 mA
= –2 mA
= 0 V,
OH
V
OH
High-level output voltage
V
OH
I
I
I
I
Short circuit output current
High-level output current
V
V
V
V
NSRT = V
NSRT = V
–20
±100
±100
±100
mA
µA
µA
µA
OS
O
O
O
O
IL
= V
= V
,
,
OH
CC
CC
IH
Off-state output current with high-level voltage applied
Off-state output current with low-level voltage applied
ENABLE = V
ENABLE = V
OZH
OZL
IL
IL
= 0 V,
15
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TMS38054
RING INTERFACE DEVICE
SPWS008C – APRIL 1991 – REVISED MAY 1997
electrical characteristics over recommended range of supply voltage (unless otherwise noted)
(continued)
wire fault (WFLT) (see Notes 8 and 9)
PARAMETER
Phantom-normal condition
TEST CONDITIONS
2.9 kΩ < R < 5.5 kΩ, 2.9 kΩ < R < 5.5 kΩ
MIN
MAX
UNIT
2.4
V
L1
L2
R
R
> 9.9 kΩ and 2.9 kΩ > R < 5.5 kΩ or
L2
L1
L2
Phantom-open condition
Phantom-short condition
0.45
0.45
V
V
> 9.9 kΩ and 2.9 kΩ < R < 5.5 kΩ
L1
R
R
< 0.1 kΩ and 2.9 kΩ < R < 5.5 kΩ or
L2
L1
L2
< 0.1 kΩ and 2.9 kΩ < R < 5.5 kΩ
L1
NOTES: 8. The wire-fault logic recognizes a load condition corresponding to greater than 9.9 kΩ to ground as an open-circuit fault, but it does
not recognize a load condition less than 5.5 kΩ to ground as an open. The wire-fault logic recognizes a load condition corresponding
to less than 100 Ω to ground as a short-circuit fault, but it does not recognize a load condition corresponding to greater than 2.9 kΩ
to ground as a short. Figure 6 illustrates this with R connected from PHOUTA to ground and R connected from PHOUTB to
L1 L2
ground.
9.
R
is connected from PHOUTA to ground; R is connected from PHOUTB to ground.
L2
L1
9.9
WFLT
Indeterminate
5.5
WFLT
High
2.9
0.1
Fault Condition
(WFLT Low)
0.0
0.0
0.1
2.9
5.5
(kΩ)
9.9
R
L1
Figure 6. Wire-Fault Pin Test
16
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TMS38054
RING INTERFACE DEVICE
SPWS008C – APRIL 1991 – REVISED MAY 1997
electrical characteristics over recommended range of supply voltage (unless otherwise noted)
(continued)
supply current
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
I
Supply current
V
CC
= 5.25 V, See Figure 7
180
200
mA
CC
75 Ω
4.1 kΩ
DROUTA
DROUTB
PHOUTA
PHOUTB
960 Ω
2.24 V
RCVR
RCLK
WFLT
REDY
NSRT
FRAQ
WRAP
2 V
ENABLE
2.49 kΩ
2.49 kΩ
VCOGAN
RCVHYS
STERES
NC
0.7 V
3 V
2 V
XTAL
RCVINA
RCVINB
16 MHz
SPSW
2.5 V
274 Ω
274 Ω
2 V
0.7 V
1 µF
DRVR
DRVR
845 Ω
16 MHz
2 V
0.7 V
FILTER
180 pF
V
CC
WDTCAP
NRGCAP
330 Ω
EQUALA
EQUALB
6800 pF
Figure 7. I
Test Circuit
CC
17
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TMS38054
RING INTERFACE DEVICE
SPWS008C – APRIL 1991 – REVISED MAY 1997
V
CC
Test
Test
Points
Points
75 Ω
75 Ω
DROUTA
DROUTB
PHOUTA
PHOUTB
PHOUTA
PHOUTB
DROUTA
DROUTB
2.24 V
2.49 kΩ
2.49 kΩ
VCOGAN
RCVHYS
965 Ω
965 Ω
965 Ω
965 Ω
RCVR
RCLK
RCVR
RCLK
REDY
NC
STERES
REDY
WFLT
RCVINA
RCVINB
WFLT
FRAQ
RCVINA
RCVINB
EQUALA
FRAQ
XTAL
XTAL
NSRT
330 Ω
NSRT
EQUALB
WDTCAP
WRAP
SPSW
ENABLE
WRAP
SPSW
V
CC
ENABLE
6800 pF
274 Ω
274 Ω
DRVR
NRGCAP
FILTER
DRVR
845 Ω
DRVR
DRVR
FILTER
1 µF
180 pF
Figure 8. ac Test Circuit
18
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TMS38054
RING INTERFACE DEVICE
SPWS008C – APRIL 1991 – REVISED MAY 1997
timing requirements over recommended range of supply voltage (unless otherwise noted)
transmitter (see Figures 8 and 9)
TEST
CONDITIONS
NO.
MIN
TYP
MAX
UNIT
Delay time, DRVR edge (1.5 V)
to following DRVR edge (1.5 V)
1
t
t
t
t
t
See Note 10
See Note 10
See Note 10
See Note 10
See Note 10
sk(DRVR)
Delay time, DRVR falling edge (1.5 V)
to DROUTA rising edge (midpoint)
2
d(DROUTA)H
d(DROUTA)L
d(DROUTB)L
d(DROUTB)H
Delay time, DRVR rising edge (1.5 V)
to DROUTA falling edge (midpoint)
3
Delay time, DRVR falling edge (1.5V)
to DROUTB falling edge (midpoint)
4
Delay time, DRVR rising edge (1.5 V)
to DROUTB rising edge (midpoint)
5
t
t
t
– t
t
t
t
t
= –1 ns
±3
±3
±2
±2
DROUTA/DROUTB
skew
d(DROUTA)H
d(DROUTB)L
sk(DRVR)
sk(DRVR)
sk(DRVR)
sk(DRVR)
6
7
ns
ns
– t
= 1 ns
= –1 ns
= 1 ns
d(DROUTA)L
d(DROUTB)H
t
t
t
DROUTA/DROUTB
asymmetry
d(DROUTA)L
d(DROUTB)H d(DROUTA)H
d(DROUTB)L
–
2
2
NOTE 10: This parameter is not tested to a minimum or a maximum but is measured and used as a component required for parameters 6 and 7.
2 V
1.5 V
0.7 V
DRVR
DRVR
2 V
1.5 V
0.7 V
1
1
100%
50%
0%
DROUTA
DROUTB
2
3
100%
50%
0%
4
5
Figure 9. Skew and Asymmetry From DRVR and DRVR to DROUTA and DROUTB
19
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TMS38054
RING INTERFACE DEVICE
SPWS008C – APRIL 1991 – REVISED MAY 1997
timing requirements over recommended range of supply voltage (unless otherwise noted)
(continued)
RCLK and RCVR (see Figures 8 and 10)
NO.
TEST CONDITIONS
MIN
46
10
35
8
TYP
MAX
UNIT
4 Mbps,
16 Mbps,
4 Mbps,
16 Mbps,
t
t
t
t
= 115 ns
= 30 ns
c(RCLK)
c(RCLK)
c(RCLK)
c(RCLK)
8
t
t
Pulse duration, RCLK low
Pulse duration, RCLK high
See Note 11
See Note 11
ns
w(RCLK)L
= 115 ns,
= 30 ns,
9
ns
w(RCLK)H
Setup time, RCVR valid to
RCLK rising edge (1.5-V point)
10
11
t
t
t
= 31.25 ns
= 31.25 ns
10
2
ns
ns
su(RCVR)
c(RCLK)
c(RCLK)
Hold time, RCVR valid after
RCLK rising edge (1.5-V point)
t
h(RCVR)
4 Mbps
125
Cycle time, RCLK
(see Note 12)
12
t
ns
c(RCLK)
16 Mbps
31.25
NOTES: 11. ThepulsedurationhighandlowofRCLKistestedatafrequencyinexcessofnominaltoensurecorrectoperationduringbriefperiods
where lock is lost.
12. This parameter is not tested. The typical value shown is that for the recovered clock from an IEEE 802.5 token ring.
12
9
8
2.4 V
1.5 V
0.45 V
RCLK
RCVR
2.4 V
Valid
0.45 V
11
10
Figure 10. RCLK and RCVR Timing
20
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TMS38054
RING INTERFACE DEVICE
SPWS008C – APRIL 1991 – REVISED MAY 1997
timing requirements over recommended range of supply voltage (unless otherwise noted)
(continued)
loop parameters (see Figures 8, 11, and 12)
TEST CONDITIONS
See Note 13
MIN
MAX
UNIT
V
Filter voltage, low
Filter voltage, high
f = 30.8 MHz,
f = 33.3 MHz,
f1 = 28.6 MHz,
2
See Note 13
3
V
VCO gain (G )
f2 = 36.4 MHz,
See Note 14
12.75 17.25 MHz/V
5.40 7.20 µA/ns
o
Phase-detector gain (G )
l
= +50 µA,
l = –50 µA, f = 32 MHz,
(FILTER)2
See Note 15
d
(FILTER)1
NOTES: 13. The frequency f is applied to XTAL with FRAQ high as shown in Figure 11. The voltage at FILTER is measured after lock is achieved.
14. A frequency of f1 is applied to the XTAL with FRAQ high. After lock is achieved, the voltage at FILTER is measured (V1). This is
repeated using f2 and measuring V2. VCO gain is calculated as (f2 – f1)/(V2 – V1). The result is in Hz/V (see external filter section).
15. The circuit of Figure 8 is used to measure phase-detector gain with I
injected at the filter test point. Figure 12 shows
the relevant timing. With the TMS38054 in phase lock, the propagation delay (t ) between RCVINA positive transition and
(FILTER)
p
RCLK negative transition is measured. A value t
is seen when l
= l
–l
, and a value of t is seen when
) ÷ (t –t ).TheresultisinµA/ns(see
p1
(FILTER)
(FILTER)1
p2
l
= l
.Thephase-detectorgainisthencalculatedas(l
(FILTER) (FILTER)2
(FILTER)2 (FILTER)1
p1 p2
external filter section).
1/f
2.4 V
XTAL (23) 1.5 V
0.45 V
Figure 11. VCO-Gain and Filter-Voltage Test Timing
RCVINB (37)
2.5 V
3 V
2 V
RCVINA (38) 2.5 V
RCLK (3) 1.5 V
t
p
V
V
OH
OL
t
c(RCLK)
Figure 12. Phase-Detector-Gain Test Timing
21
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TMS38054
RING INTERFACE DEVICE
SPWS008C – APRIL 1991 – REVISED MAY 1997
timing requirements over recommended range of supply voltage (unless otherwise noted)
(continued)
data recovery (see Figures 8 and 13 and Note 16)
NO.
TEST CONDITIONS
MIN
MAX
±20
UNIT
4 Mbps,
16 Mbps,
f = 8 MHz
Static timing error from voltage midpoint of RCVINA edge
to midpoint to RCVINA pulse
13
t
se
ns
f = 32 MHz
±3.62
NOTE 16: The TMS38054 is phase locked to a RCVINA waveform as shown in Figure 13 with RCVINB biased to 2.5 V. RCVR is monitored for
properdata being latched. For one pulse, shorten the time at which RCVINA’s negative transition occurs. Check RCVR if the short pulse
was latched. Restabilize the VCO with normal pulses. Input another short pulse. Continue this routine, while gradually shortening the
pulse, untilthedataisnotlatched. Thetimebetweenthisnegativetransitionandthemidpointoftheoriginalpulse’suptime is t . Repeat
se
this procedure using all of the RCVINA waveforms shown.
1/f
1/(2f)
3 V
RCVINA (38) 2.5 V
Midpoint
2 V
13
3 V
RCVINA (38) 2.5 V
2 V
13
13
3 V
RCVINA (38) 2.5 V
2 V
13
3 V
RCVINA (38) 2.5 V
2 V
V
OH
RCVR (2) 15 V
V
OL
Figure 13. TMS38054 Phase Locked to RCVINA
22
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TMS38054
RING INTERFACE DEVICE
SPWS008C – APRIL 1991 – REVISED MAY 1997
timing requirements over recommended range of supply voltage (unless otherwise noted)
(continued)
energy detect (REDY) (see Figure 8 and Note 17)
NO.
TEST CONDITIONS
MIN
2
MAX
UNIT
Data transition density = 100%, See Figure 14
Delay time,
FRAQ transition to REDY low again
14
t
t
µs
d(REDYHL)
Data transition density = 33%,
See Figure 14
6
100
100
Delay time,
data loss to REDY high
Data transition density changes 100% to 2.5%,
See Figure 15
15
20
µs
d(REDYH)
NOTE 17: The transition density of the incoming data is the percentage of transitions of the incoming data as compared to the maximum possible
number of transitions. For a string of Manchester-encoded 0 data, 100% transition density is a 16-MHz signal at a 16-Mbps data
transmission rate.
3 V
Data at Specified Transition Density
RCVINA
RCVINB
2 V
2.5 V
2 V
FRAQ
REDY
0.7 V
2.4 V
0.45 V
14
Figure 14. Timing Waveforms for Energy-Detect, FRAQ to REDY Timing
3 V
2 V
100% Transition Density
2.5% Transition Density
RCVINA
RCVINB
2.5 V
2 V
FRAQ
REDY
0.7 V
2.4 V
0.45 V
15
Figure 15. Timing Waveforms for Energy-Detect to Energy-Loss Timing
23
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TMS38054
RING INTERFACE DEVICE
SPWS008C – APRIL 1991 – REVISED MAY 1997
timing requirements over recommended range of supply voltage (unless otherwise noted)
(continued)
watchdog timer (see Figures 16 and Notes 9, 18, 19, 20)
NO.
TEST CONDITIONS
= 1.5 µF, = R = 2.9 kΩ
MIN
MAX
UNIT
16
t
Delay time, watchdog-timer expiration
L2
C
R
21
50
ms
d(WDT)H
wdt
L1
L2
NOTES: 9.
R
L1
is connected from PHOUTA to ground; R is connected from PHOUTB to ground.
18. To enable the phantom-driver signals, NRST must be toggled high with a maximum 20-ms period (50-Hz repetition rate).
Phantom-driver signals are assured to be disabled if NRST does not toggle for 50 ms. The ’380C2x software ensures a maximum
20-ms period toggling rate for the insertion condition.
19. Pulse duration high of NSRT is not critical, but it is recommended that it be at least 125 ns.
20.
C
is the capacitor connected from WDTCAP to GND.
wdt
Data at Specified Transition Density
2 V
NRST
0.7 V
3 V
PHOUTA/PHOUTB
0.45 V
16
Figure 16. Watchdog-Timer Expiration Waveforms
24
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
TMS38054
RING INTERFACE DEVICE
SPWS008C – APRIL 1991 – REVISED MAY 1997
MECHANICAL DATA
FN (S-PQCC-J**)
PLASTIC J-LEADED CHIP CARRIER
20 PIN SHOWN
Seating Plane
0.004 (0,10)
0.180 (4,57) MAX
0.120 (3,05)
D
0.090 (2,29)
D1
0.020 (0,51) MIN
3
1
19
0.032 (0,81)
0.026 (0,66)
4
18
D2/E2
D2/E2
E
E1
8
14
0.021 (0,53)
0.013 (0,33)
0.050 (1,27)
9
13
0.007 (0,18)
M
0.008 (0,20) NOM
D/E
D1/E1
D2/E2
NO. OF
PINS
**
MIN
0.385 (9,78)
MAX
MIN
MAX
MIN
MAX
0.395 (10,03)
0.350 (8,89)
0.356 (9,04)
0.141 (3,58)
0.191 (4,85)
0.291 (7,39)
0.341 (8,66)
0.169 (4,29)
0.219 (5,56)
0.319 (8,10)
0.369 (9,37)
20
28
44
52
68
84
0.485 (12,32) 0.495 (12,57) 0.450 (11,43) 0.456 (11,58)
0.685 (17,40) 0.695 (17,65) 0.650 (16,51) 0.656 (16,66)
0.785 (19,94) 0.795 (20,19) 0.750 (19,05) 0.756 (19,20)
0.985 (25,02) 0.995 (25,27) 0.950 (24,13) 0.958 (24,33) 0.441 (11,20) 0.469 (11,91)
1.185 (30,10) 1.195 (30,35) 1.150 (29,21) 1.158 (29,41) 0.541 (13,74) 0.569 (14,45)
4040005/B 03/95
NOTES: A. All linear dimensions are in inches (millimeters).
B. This drawing is subject to change without notice.
C. Falls within JEDEC MS-018
25
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
PACKAGE OPTION ADDENDUM
www.ti.com
24-Jun-2005
PACKAGING INFORMATION
Orderable Device
Status (1)
Package Package
Pins Package Eco Plan (2) Lead/Ball Finish MSL Peak Temp (3)
Qty
Type
PLCC
PLCC
TQFP
LQFP
Drawing
TMS38054FNL
TMS38054FNLR
TMS38054PAH
TMS38054PBGL
OBSOLETE
OBSOLETE
OBSOLETE
OBSOLETE
FN
44
44
52
52
TBD
TBD
TBD
TBD
Call TI
Call TI
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Call TI
FN
PAH
PBG
(1) The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in
a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2)
Eco Plan
-
The planned eco-friendly classification: Pb-Free (RoHS) or Green (RoHS
&
no Sb/Br)
-
please check
http://www.ti.com/productcontent for the latest availability information and additional product content details.
TBD: The Pb-Free/Green conversion plan has not been defined.
Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements
for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered
at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes.
Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame
retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material)
(3)
MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder
temperature.
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Addendum-Page 1
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