SP3485EN-L

Part: SP3485

Type: 3.3V Low Power Half-Duplex RS-485 Transceiver

Key Specs:

• Supply Voltage: 3.3V
• Maximum Data Rate: 10 Mbps
• Common-Mode Input Voltage Range: -7V to +12V
• Max Transceivers on Bus: 32
• ESD Rating (HBM): ±2kV

Features:

• RS-485 and RS-422 transceiver
• Operates from a single 3.3V supply
• Interoperable with 5.0V logic
• Driver/receiver enable
• -7V to +12V common-mode input voltage range
• Allows up to 32 transceivers on the serial bus
• Compatibility with industry standard 75176 pinout
• Driver output short-circuit protection

Applications: null

Package: null

• RS-485 and RS-422 transceiver
• Operates from a single 3.3V supply
• Interoperable with 5.0V logic
• Driver/receiver enable
• -7V to +12V common-mode input voltage range
• Allows up to 32 transceivers on the serial bus
• Compatibility with industry standard 75176 pinout
• Driver output short-circuit protection

Ordering Information - Back Page

Block Diagram

SP3485

Pin	Name	Description
1	RO	Receiver output
2	RE	Receiver output enable active LOW
3	DE	Driver output enable active HIGH
4	DI	Driver input
5	GND	Ground connection
6	A	Non-inverting driver output / receiver input
7	B	Inverting driver output / receiver input
8	VCC	Positive supply

Pinout (Top View)

Unless otherwise noted: TAMB = TMIN to TMAX and VCC = 3.3V ±5%.

PARAMETERS	MIN.	TYP.	MAX.	UNITS	CONDITIONS
SP3485 Driver DC Characteristics
Differential output voltage			Vcc	Volts	Unloaded; R = ∞Ω ; Figure 1
Differential output voltage	2		Vcc	Volts	With Load; R = 50Ω (RS-422); Figure 1
Differential output voltage	1.5		Vcc	Volts	With Load; R = 27Ω (RS-485); Figure 1
Change in magnitude of driver differential output voltage for complimentary states			0.2	Volts	R = 27Ω or R = 50Ω; Figure 1
Driver common mode output voltage			3	Volts	R = 27Ω or R = 50Ω; Figure 1
Input high voltage	2.0			Volts	Applies to DE, DI, RE
Input low voltage			0.8	Volts	Applies to DE, DI, RE
Input current			±10	μA	Applies to DE, DI, RE
Driver short circuit current VOUT = HIGH			±250	mA	-7V ≤ VO ≤ +12V; Figure 8
Driver short circuit current VOUT = LOW			±250	mA	-7V ≤ VO ≤ +12V; Figure 8
SP3485 Driver AC Characteristics
Maximum data rate	10			Mbps	RE = VCC, DE = VCC
Driver input to output, tPLH		17	60	ns	Figures 2 & 9
Driver input to output, tPHL		17	60	ns	Figures 2 & 9
Differential driver skew		2	10	ns	tDO1- tDO2 , Figures 2 and 10
Driver rise or fall time		5	20	ns	From 10%-90%; Figures 3 and 10
Driver enable to output high		35	120	ns	Figures 4 and 11
Driver enable to output low		30	120	ns	Figures 5 and 11
Driver disable time from low		20	120	ns	Figures 5 and 11
Driver disable time from high		20	120	ns	Figures 4 and 11
Driver enable from shutdown to output high, tPSH			250	ns	CL = 50pF, RL = 500Ω.
Driver enable from shutdown to output low, t PSL			250	ns	Figures 4, 5, and 11
Time to shutdown, tSHDN	50	200	600	ns	Notes 1 and 2

These are stress ratings only and functional operation of the device at these ratings or any other above those indicated in the operation sections of the specifications below is not implied. Exposure to absolute maximum rating conditions for extended periods of time may affect reliability.

VCC	3.3V
Input Voltages
Logic
Drivers
Receivers	-7V to +12V
Outputs
Drivers
Receivers
Receiver Output Current
Storage Temperature
Maximum Junction Temperature, TJ
Power Dissipation
(derate 6.90mW/°C above 70°C)

Operating Conditions

Package Power Dissipation

ESD Rating

Human Body Model (HBM).......................................... ±2kV

Electrical Characteristics

Unless otherwise noted: TAMB = TMIN to TMAX and VCC = 3.3V ±5%.

PARAMETERS	MIN.	TYP.	MAX.	UNITS	CONDITIONS
SP3485 Driver DC Characteristics
Differential output voltage			Vcc	Volts	Unloaded; R = ∞Ω ; Figure 1
Differential output voltage	2		Vcc	Volts	With Load; R = 50Ω (RS-422); Figure 1
Differential output voltage	1.5		Vcc	Volts	With Load; R = 27Ω (RS-485); Figure 1
Change in magnitude of driver differential output voltage for complimentary states			0.2	Volts	R = 27Ω or R = 50Ω; Figure 1
Driver common mode output voltage			3	Volts	R = 27Ω or R = 50Ω; Figure 1
Input high voltage	2.0			Volts	Applies to DE, DI, RE
Input low voltage			0.8	Volts	Applies to DE, DI, RE
Input current			±10	μA	Applies to DE, DI, RE
Driver short circuit current VOUT = HIGH			±250	mA	-7V ≤ VO ≤ +12V; Figure 8
Driver short circuit current VOUT = LOW			±250	mA	-7V ≤ VO ≤ +12V; Figure 8
SP3485 Driver AC Characteristics
Maximum data rate	10			Mbps	RE = VCC, DE = VCC
Driver input to output, tPLH		17	60	ns	Figures 2 & 9
Driver input to output, tPHL		17	60	ns	Figures 2 & 9
Differential driver skew		2	10	ns	tDO1- tDO2 , Figures 2 and 10
Driver rise or fall time		5	20	ns	From 10%-90%; Figures 3 and 10
Driver enable to output high		35	120	ns	Figures 4 and 11
Driver enable to output low		30	120	ns	Figures 5 and 11
Driver disable time from low		20	120	ns	Figures 5 and 11
Driver disable time from high		20	120	ns	Figures 4 and 11
Driver enable from shutdown to output high, tPSH			250	ns	CL = 50pF, RL = 500Ω.
Driver enable from shutdown to output low, t PSL			250	ns	Figures 4, 5, and 11
Time to shutdown, tSHDN	50	200	600	ns	Notes 1 and 2