Linear Technology LTC1546 Datasheet

Final Electrical Specifications

FEATURES

■

Software-Selectable Transceiver Supports:
RS232, RS449, EIA530, EIA530-A, V.35, V.36, X.21

■

TUV Telecom Services Inc. Certified NET1,
NET2 and TBR2 Compliant

■

On-Chip Cable Termination

■

Pin Compatible with LTC1543

■

Complete DTE or DCE Port with LTC1544

■

Operates from Single 5V Supply

■

Small Footprint

LTC1546

Software-Selectable

Multiprotocol Transceiver

with Termination

December 1999

U

DESCRIPTIO

The LTC®1546 is a 3-driver/3-receiver multiprotocol trans­ceiver with on-chip cable termination. When combined with
the LTC1544, this chip set forms a complete software­selectable DTE or DCE interface port that supports the
RS232, RS449, EIA530, EIA530-A, V.35, V.36 and X.21
protocols. All necessary cable termination is provided inside
the LTC1546. In most applications, the LTC1546 replaces
both an LTC1543 and an LTC1344A without any changes to
the PC board.

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APPLICATIO S

■

Data Networking

■

CSU and DSU

■

Data Routers

TYPICAL APPLICATIO

Complete DTE or DCE Multiprotocol Serial Interface with DB-25 Connector

LL

D4

R2 R1R4

R3

U

LTC1544

D3

DTRDSR DCDCTS

D2 D1

RTS

The LTC1546 runs from a single 5V supply using an internal
charge pump that requires only five space-saving surface
mounted capacitors. The LTC1546 is available in a 28-lead
SSOP surface mount package.

, LTC and LT are registered trademarks of Linear Technology Corporation.

RXCRXD

LTC1546

R1R2R3

TXDSCTETXC

D1

D2D3

TTTTT

CTS B

LL A (141)

DSR A (109)

DSR B

CTS A (106)

Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen­tation that the interconnection of its circuits as described herein will not infringe on existing patent rights.

DCD A (107)

DCD B

DTR B

RTS A (105)

RTS B

DTR A (108)

SG (102)

SHIELD (101)

RXD B

DB-25 CONNECTOR

RXC B

RXD A (104)

RXC A (115)

TXC B

TXC A (114)

SCTE B

SCTE A (113)

TXD B

21424111512179314192062322513 81018 7 16

TXD A (103)

1546 TA01

1

LTC1546

PACKAGE/ORDER I FOR ATIO

UU

W

WWWU

ABSOLUTE AXI U RATI GS

(Note 1)

Supply Voltage ....................................................... 6.5V

Input Voltage

Transmitters ........................... –0.3V to (VCC + 0.3V)

Receivers............................................... –18V to 18V

Logic Pins .............................. –0.3V to (VCC + 0.3V)

Output Voltage

Transmitters ................. (VEE – 0.3V) to (VDD + 0.3V)

Receivers................................ –0.3V to (VCC + 0.3V)

VEE........................................................ –10V to 0.3V

VDD....................................................... –0.3V to 10V

Short-Circuit Duration

Transmitter Output ..................................... Indefinite

Receiver Output.......................................... Indefinite

VEE.................................................................. 30 sec

Operating Temperature Range

LTC1546C ............................................... 0°C to 70°C

LTC1546I........................................... –40°C to 85°C

Storage Temperature Range ................ –65°C to 150°C

Lead Temperature (Soldering, 10 sec)................. 300°C

TOP VIEW

–

1

C1

+

2

C1

3

V

DD

4

V

CC

5

D1

6

D2

7

D3

8

R1

9

R2

10

R3

11

M0

12

M1

13

M2

14

DCE/DTE

*θJA SOLDERED TO A TYPICAL CIRCUIT BOARD
IS TYPICALLY 60°C/W

CHARGE PUMP

D1

D2

D3

R1

R2

R3

G PACKAGE

28-LEAD PLASTIC SSOP

T

= 150°C, θJA = 90°C/W*

JMAX

T

T

ORDER PART

+

C2

28

–

C2

27

V

26

EE

GND

25

D1 A

24

D1 B

23

D2 A

22

D2 B

21

D3/R1 A

20

T

D3/R1 B

19

R2 A

18

T

R2 B

17

R3 A

16

T

R3 B

15

NUMBER

LTC1546CG
LTC1546IG

Consult factory for Military grade parts.

ELECTRICAL CHARACTERISTICS

The ● denotes specifications which apply over the full operating

temperature range, otherwise specifications are at TA = 25°C. VCC = 5V (Notes 2, 3)

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Supplies

I

CC

P

D

+

V

–

V

VCC Supply Current (DCE Mode, RS530, RS530-A, X.21 Modes, No Load 14 mA
All Digital Pins = GND or V

) RS530, RS530-A, X.21 Modes, Full Load ● 100 130 mA

CC

V.35 Mode

● 126 170 mA

V.28 Mode, No Load 20 mA
V.28 Mode, Full Load ● 35 75 mA
No-Cable Mode

● 60 500 µA

Internal Power Dissipation (DCE Mode) RS530, RS530-A, X.21 Modes, Full Load 410 mW

V.35 Mode, Full Load 625 mW
V.28 Mode, Full Load 150 mW

Positive Charge Pump Output Voltage V.11 or V.28 Mode, No Load ● 8.0 9.3 V

V.35 Mode
V.28 Mode, with Load
V.28 Mode, with Load, I

= 10mA 6.5 V

DD

● 7.0 8.0 V

● 8.0 8.7 V

Negative Charge Pump Output Voltage V.28 Mode, No Load –9.6 V

V.28 Mode, Full Load
V.35 Mode
RS530, RS530-A, X.21 Modes, Full Load

● – 7.5 –8.5 V

● – 5.5 –6.5 V

● – 4.5 –6.0 V

2

LTC1546

ELECTRICAL CHARACTERISTICS

The ● denotes specifications which apply over the full operating

temperature range, otherwise specifications are at TA = 25°C. VCC = 5V (Notes 2, 3)

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

f

OSC

t

r

Logic Inputs and Outputs

V

IH

V

IL

I

IN

V

OH

V

OL

I

OSR

I

OZR

V.11 Driver

V

ODO

V

ODL

∆V

OD

V

OC

∆V

OC

I

SS

I

OZ

tr, t

f

t

PLH

t

PHL

∆t Input to Output Difference, t
t

SKEW

V.11 Receiver

V

TH

∆V

TH

R

IN

tr, t

f

t

PLH

t

PHL

∆t Input to Output Difference, t

V.35 Driver

V

OD

VOA, V
V

OC

Charge Pump Oscillator Frequency 500 kHz
Charge Pump Rise Time No-Cable Mode/Power-Off to Normal Operation 2 ms

Logic Input High Voltage ● 2V
Logic Input Low Voltage ● 0.8 V
Logic Input Current D1, D2, D3 ● ±10 µA

M0, M1, M2, DCE = GND
M0, M1, M2, DCE = V

CC

● –120 –75 – 30 µA

● ±10 µA

Output High Voltage IO = –3mA ● 3 4.5 V
Output Low Voltage IO = 3mA ● 0.3 0.45 V
Output Short-Circuit Current 0V ≤ VO ≤ V

CC

Three-State Output Current M0 = M1 = M2 = VCC, 0V ≤ VO ≤ V

CC

● –50 50 mA

±1 µA

Open Circuit Differential Output Voltage RL = 1.95k (Figure 1) ● ±5V
Loaded Differential Output Voltage RL = 50Ω (Figure 1) 0.5V

= 50Ω (Figure 1) ● ±2V

R

L

ODO

0.67V

ODO

Change in Magnitude of Differential RL = 50Ω (Figure 1) ● 0.2 V
Output Voltage

Common Mode Output Voltage RL = 50Ω (Figure 1) ● 3V
Change in Magnitude of Common Mode RL = 50Ω (Figure 1) ● 0.2 V

Output Voltage
Short-Circuit Current V
Output Leakage Current V

= GND ±150 mA

OUT

 and VB ≤ 0.25V, Power Off or ● ±1 ±100 µA

A

No-Cable Mode or Driver Disabled

Rise or Fall Time (Figures 2, 13) ● 21525 ns
Input to Output Rising (Figures 2, 13) ● 15 40 65 ns
Input to Output Falling (Figures 2, 13) ● 15 40 65 ns

– t

PLH

 (Figures 2, 13) ● 0312 ns

PHL

Output to Output Skew (Figures 2, 13) 3 ns

Input Threshold Voltage –7V ≤ VCM ≤ 7V ● –0.2 0.2 V
Input Hysteresis –7V ≤ VCM ≤ 7V ● 15 40 mV
Input Impedance –7V ≤ VCM ≤ 7V (Figure 3) ● 100 103 Ω
Rise or Fall Time CL = 50pF (Figures 4, 14) 15 ns
Input to Output Rising CL = 50pF (Figures 4, 14) ● 50 90 ns
Input to Output Falling CL = 50pF (Figures 4, 14) ● 50 90 ns

– t

 C

PLH

PHL

= 50pF (Figures 4, 14) ● 0425 ns

L

Differential Output Voltage Open Circuit, RL = 1.95k (Figure 5) ● ±1.2 V

With Load, –4V ≤ V

Single-Ended Output Voltage Open Circuit, RL = 1.95k (Figure 5) ● ±1.2 V

OB

≤ 4V (Figure 6) ±0.44 ±0.55 ±0.66 V

CM

Transmitter Output Offset RL = 50Ω (Figure 5) ● ±0.6 V

V

3

LTC1546

ELECTRICAL CHARACTERISTICS

The ● denotes specifications which apply over the full operating

temperature range, otherwise specifications are at TA = 25°C. VCC = 5V (Notes 2, 3)

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

I

OH

I

OL

I

OZ

R

OD

R

OC

tr, t

f

t

PLH

t

PHL

∆t Input to Output Difference, t
t

SKEW

V.35 Receiver

V

TH

∆V

TH

R

ID

R

IC

tr, t

f

t

PLH

t

PHL

∆t Input to Output Difference, t

V.28 Driver

V

O

I

SS

R

OZ

SR Slew Rate RL = 7k, CL = 0 (Figures 11, 15) ● 430V/µs
t

PLH

t

PHL

V.28 Receiver
V

THL

V

TLH

∆V

TH

R

IN

tr, t

f

t

PLH

t

PHL

Transmitter Output High Current VA, VB = 0V ● – 13 –11 – 9.0 mA
Transmitter Output Low Current VA, VB = 0V ● 9.0 11 13 mA
Transmitter Output Leakage Current V

 and VB ≤ 0.25V ● ±1 ±100 µA

A

Transmitter Differential Mode Impedance ● 50 100 150 Ω
Transmitter Common Mode Impedance – 2V ≤ VCM ≤ 2V (Figure 7) 135 150 165 Ω
Rise or Fall Time (Figures 8, 13) 5 ns
Input to Output (Figures 8, 13) ● 15 35 65 ns
Input to Output (Figures 8, 13) ● 15 35 65 ns

– t

PLH

 (Figures 8, 13) ● 016 ns

PHL

Output to Output Skew (Figures 8, 13) 4 ns

Differential Receiver Input Threshold Voltage –2V ≤ VCM ≤ 2V (Figure 9) ● –0.2 0.2 V
Receiver Input Hysteresis –2V ≤ VCM ≤ 2V (Figure 9) ● 15 40 mV
Receiver Differential Mode Impedance –2V ≤ VCM ≤ 2V ● 90 103 110 Ω
Receiver Common Mode Impedance –2V ≤ VCM ≤ 2V (Figure 10) 135 150 165 Ω
Rise or Fall Time CL = 50pF (Figures 4, 14) 15 ns
Input to Output CL = 50pF (Figures 4, 14) ● 50 90 ns
Input to Output CL = 50pF (Figures 4, 14) ● 50 90 ns

– t

PLH

 C

PHL

= 50pF (Figures 4, 14) ● 0425 ns

L

Output Voltage Open Circuit ● ±10 V

= 3k (Figure 11) ● ±5 ±8.5 V

R

L

Short-Circuit Current V

= GND ● ±150 mA

OUT

Power-Off Resistance –2V < VO < 2V, Power Off ● 300 Ω

or No-Cable Mode

Input to Output RL = 3k, CL = 2500pF (Figures 11, 15) ● 1.5 2.5 µs
Input to Output RL = 3k, CL = 2500pF (Figures 11, 15) ● 1.5 2.5 µs

Input Low Threshold Voltage (Figure 12) ● 1.2 0.8 V
Input High Threshold Voltage (Figure 12) ● 2 1.2 V
Receiver Input Hysteresis (Figure 12) ● 0 0.05 0.3 V
Receiver Input Impedance – 15V ≤ VA ≤ 15V ● 357 kΩ
Rise or Fall Time CL = 50pF (Figures 12, 16) 15 ns
Input to Output CL = 50pF (Figures 12, 16) ● 60 300 ns
Input to Output CL = 50pF (Figures 12, 16) ● 160 300 ns

Note 1: Absolute Maximum Ratings are those values beyond which the life
of the device may be impaired.

Note 2: All currents into device pins are positive; all currents out of device
are negative. All voltages are referenced to device ground unless otherwise
specified.

4

Note 3: All typicals are given for V

= 3.3µF and TA = 25°C.

C

VEE

= 5V, C1 = C2 = C

CC

VCC

= C

VDD

= 1µF,

LTC1546

U

UU

PI FU CTIO S

C1–␣ (Pin 1): Capacitor C1 Negative Terminal. Connect a
1µF capacitor between C1+ and C1–.

C1+ (Pin 2): Capacitor C1 Positive Terminal. Connect a
1µF capacitor between C1+ and C1–.

VDD (Pin 3): Generated Positive Supply Voltage for
V.28. Connect a 1µF capacitor to ground.

VCC (Pin 4): Positive Supply Voltage Input. 4.75V ≤ V
≤ 5.25V. Bypass with a 1µF capacitor to ground.

D1 (Pin 5): TTL Level Driver 1 Input.
D2 (Pin 6): TTL Level Driver 2 Input.
D3 (Pin 7): TTL Level Driver 3 Input.
R1 (Pin 8): CMOS Level Receiver 1 Output.
R2 (Pin 9): CMOS Level Receiver 2 Output.
R3 (Pin 10): CMOS Level Receiver 3 Output.
M0 (Pin 11): TTL Level Mode Select Input 0 with Pull-Up

to VCC. See Table 1.
M1 (Pin 12): TTL Level Mode Select Input 1 with Pull-Up

to VCC. See Table 1.
M2 (Pin 13): TTL Level Mode Select Input 2 with Pull-Up

to VCC. See Table 1.

CC

R3 B (Pin 15): Receiver 3 Noninverting Input.
R3 A (Pin 16): Receiver 3 Inverting Input.
R2 B (Pin 17): Receiver 2 Noninverting Input.
R2 A (Pin 18): Receiver 2 Inverting Input.
D3/R1 B (Pin 19): Receiver 1 Noninverting Input and

Driver 3 Noninverting Output.
D3/R1 A (Pin 20): Receiver 1 Inverting Input and Driver 3

Inverting Output.

D2 B (Pin 21): Driver 2 Noninverting Output.
D2 A (Pin 22): Driver 2 Inverting Output.
D1 B (Pin 23): Driver 1 Noninverting Output.
D1 A (Pin 24): Driver 1 Inverting Output.
GND (Pin 25): Ground.
VEE (Pin 26): Negative Supply Voltage. Connect a 3.3µF

capacitor to GND.
C2– (Pin 27): Capacitor C2 Negative Terminal. Connect a

1µF capacitor between C2+ and C2–.
C2+ (Pin 28): Capacitor C2 Positive Terminal. Connect a

1µF capacitor between C2+ and C2–.

DCE/DTE (Pin 14): TTL Level Mode Select Input with Pull­Up to VCC. See Table 1.

5

LTC1546

BLOCK DIAGRA

W

CHARGE

PUMP

–

C1

+

C1

2

V

3

DD

V

4

CC

50Ω

–

+

C1

C2

+

–

C1

C2

V

V

DD

EE

V

GND

CC

+

C2

281

–

C2

27

V

26

EE

GND

25

D1A

24

DCE/DTE

D1

D2

D3

R1

R2

D1

5

D2

6

D3

7

14

8

9

S1

S2

125Ω

50Ω

D1B

23

22

D2A

50Ω

S1

S2

125Ω

50Ω

D2B

21

20

19

18

D3/R1 A

D3/R1 B

R2A

20k

10k 6k

S3

S2

10k

20k

R1

20k

6k

10k

R2

S3

S2

125Ω

51.5Ω

S1

125Ω

51.5Ω

51.5Ω

6

10k

20k
20k

6k

10k

R3

10

R3

10k

20k

S3

S2

125Ω

51.5Ω

51.5Ω

51.5Ω

R2B

17

R3A

16

R3B

15

1546 BD