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REV: 061208

Note: Some revisions of this device may incorporate deviations from published specifications known as errata. Multiple revisions of any device

may be simultaneously available through various sales channels. For information about device errata, click here: www.maxim-ic.com/errata

GENERAL DESCRIPTION

The DS2482-100 is an I

C to 1-Wire® bridge device

that interfaces directly to standard (100kHz max) or

fast (400kHz max) I

C masters to perform

bidirectional protocol conversion between the I

master and any downstream 1-Wire slave devices.

Relative to any attached 1-Wire slave device, the

DS2482-100 is a 1-Wire master. Internal factory

trimmed timers relieve the system host processor

from generating time-critical 1-Wire waveforms,

supporting both standard and Overdrive 1-Wire

communication speeds. To optimize 1-Wire waveform

generation, the DS2482-100 performs slew rate

control on rising and falling 1-Wire edges and

provides additional programmable features to match

drive characteristics to the 1-Wire slave environment.

Programmable strong pullup features support 1-Wire

power delivery to 1-Wire devices such as EEPROMs

and sensors. The DS2482-100 combines these

features with an output to control an external

MOSFET for enhanced strong pullup application. The

I²C slave address assignment is controlled by two

binary address inputs, resolving potential conflicts

with other I

C slave devices in the system.

APPLICATIONS

Printers

Medical Instruments

Industrial Sensors

Cell Phones, PDAs

TYPICAL OPERATING CIRCUIT

1-Wire line

DS2482-100

PCTLZ

Current Limiting

Resistor

(I²C port)

µC

SDA

SCL

AD0

AD1

1-Wire

Device

1-Wire

Device

1-Wire

Device

Optional

circuitry

1-Wire is a registered trademark of Maxim Integrated Products, Inc.

FEATURES

 I

C Host Interface, Supports 100kHz and 400kHz

C Communication Speeds

 1-Wire Master IO with Selectable Active or

Passive 1-Wire Pullup

 Provides Reset/Presence, 8-Bit, Single-Bit, and

Three-Bit 1-Wire IO Sequences

 Standard and Overdrive 1-Wire Communication

Speeds

 Slew Controlled 1-Wire Edges

 Selectable 1-Wire Slave Presence-Pulse Falling

Edge Masking to Control Fast Edges on the

1-Wire Line

 Strong 1-Wire Pullup Provided by an Internal

Low-Impedance Signal Path

 PCTLZ Output to Optionally Control an External

MOSFET for Stronger Pullup Requirements

 Two Address Inputs for I

C Address Assignment

 Operating Range: 2.9V to 5.5V, -40°C to +85°C

 8-Pin, 150-mil SO Package and 9 WLP Package

ORDERING INFORMATION

PART TEMP RANGE PIN-PACKAGE

DS2482S-100+

-40°C to +85°C

8 SO (150 mils)

DS2482S-100+T&R

-40°C to +85°C

8 SO (150 mils)

DS2482X-100+T

-40°C to +85°C

9 WLP (2.5k pcs)

+Denotes a lead-free/RoHS-compliant package.

T/T&R = Tape and reel.

PIN CONFIGURATIONS

WLP, Top View with Laser

Mark, Contacts Not Visible.

See 21-0067 for WLP package outline drawing.

yywwrr = Date/Revision

###xx = Lot Number

1 = PCTLZ

2 = AD1

3 = AD0

B1 = SCL

B2 = SDA

B3 = VCC

C2 = GND

C3 = IO

1 Mark

1 2 3

4821

yywwrr

##xx

PCTLZ

SDA

VCC

GND

SCL

DS2482-100

Single-Channel 1-Wire Maste

www.maxim-ic.com

Summary of content (22 pages)

PAGE 1
DS2482-100 Single-Channel 1-Wire Master www.maxim-ic.com GENERAL DESCRIPTION FEATURES 2 The DS2482-100 is an I C to 1-Wire® bridge device that interfaces directly to standard (100kHz max) or fast (400kHz max) I2C masters to perform bidirectional protocol conversion between the I2C master and any downstream 1-Wire slave devices. Relative to any attached 1-Wire slave device, the DS2482-100 is a 1-Wire master.
PAGE 2
DS2482-100: Single-Channel 1-Wire Master ABSOLUTE MAXIMUM RATINGS Voltage Range on Any Pin Relative to Ground Maximum Current into Any Pin Operating Temperature Range Junction Temperature Storage Temperature Range Soldering Temperature -0.5V, +6V ±20mA -40°C to +85°C +150°C -55°C to +125°C Refer to the IPC/JEDEC J-STD-020 Specification. Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device.
PAGE 3
DS2482-100: Single-Channel 1-Wire Master PARAMETER SYMBOL CONDITIONS Reset High Time tRSTH Presence-Pulse Mask START Presence-Pulse Mask STOP tPPM1 tPPM2 Standard Overdrive Standard Overdrive Standard Overdrive Standard Overdrive Standard Overdrive Standard Overdrive (Note 8) (Note 8) Output-Low Voltage VOLP VCC = 2.9V, 1.2mA load current Output-High Voltage VOHP 0.
PAGE 4
DS2482-100: Single-Channel 1-Wire Master PARAMETER SYMBOL Data Hold Time Data Setup Time Setup Time for STOP Condition Bus Free Time Between a STOP and START Condition Capacitive Load for Each Bus Line Oscillator Warm-Up Time Note 1: Note 2: Note 3: Note 4: Note 5: Note 6: Note 7: Note 8: Note 9: Note 10: Note 11: Note 12: Note 13: Note 14: Note 15: Note 16: MAX UNITS 0.9 250 µs ns tSU:STO 0.6 µs tBUF 1.
PAGE 5
DS2482-100: Single-Channel 1-Wire Master Figure 1. Block Diagram DS2482-100 Config Register I²C Interface Controller SDA SCL T-Time OSC I/O Controller Line XCVR IO PCTLZ Status Register AD0 AD1 Read Data Register DETAILED DESCRIPTION The DS2482-100 is a self-timed 1-Wire master, which supports advanced 1-Wire waveform features including standard and Overdrive speeds, active pullup, strong pullup for power delivery, and presence-pulse masking.
PAGE 6
DS2482-100: Single-Channel 1-Wire Master Active Pullup (APU) The APU bit controls whether an active pullup (controlled slew-rate transistor) or a passive pullup (RWPU resistor) is used to drive a 1-Wire line from low to high. When APU = 0, active pullup is disabled (resistor mode). Active Pullup should be selected if the 1-Wire line has a substantial length (several 10m) or if there is a large number (~20 or more) of devices connected to a 1-Wire line.
PAGE 7
DS2482-100: Single-Channel 1-Wire Master Strong Pullup (SPU) The SPU bit is used to activate the strong pullup function prior to a 1-Wire Write Byte or 1-Wire Single Bit command. Strong pullup is commonly used with 1-Wire EEPROM devices when copying scratchpad data to the main memory or when performing an SHA-1 computation, and with parasitically powered temperature sensors or A/D converters.
PAGE 8
DS2482-100: Single-Channel 1-Wire Master Status Register The read-only Status register is the general means for the DS2482-100 to report bit-type data from the 1-Wire side, 1-Wire busy status and its own reset status to the host processor. All 1-Wire communication commands and the Device Reset command position the read pointer at the Status register for the host processor to read with minimal protocol overhead. Status information is updated during the execution of certain commands only.
PAGE 9
DS2482-100: Single-Channel 1-Wire Master FUNCTION COMMANDS The DS2482-100 understands eight function commands, which fall into four categories: device control, I2C communication, 1-Wire setup, and 1-Wire communication. The feedback path to the host is controlled by a read pointer, which is set automatically by each function command for the host to efficiently access relevant information.
PAGE 10
DS2482-100: Single-Channel 1-Wire Master Write Configuration Command Code Command Parameter Description Typical Use Restriction Error Response Command Duration 1-Wire Activity Read Pointer Position Status Bits Affected Configuration Bits Affected D2h Configuration Byte Writes a new configuration byte. The new settings take effect immediately.
PAGE 11
DS2482-100: Single-Channel 1-Wire Master Figure 5. 1-Wire Reset/Presence Detect Cycle RESET PULSE PRESENCE/SHORT DETECT tSI VCC tMSP VIH1 VIL1 0V tF1 tRSTL tRSTH Pull-up DS2482 pull-down 1-W Slave pull down For presence pulse masking and pull-up details see Figure 3.
PAGE 12
DS2482-100: Single-Channel 1-Wire Master Figure 6. Write-0 Time Slot tW0L Vcc tMSR VIH1 VIL1 0V tREC0 tF1 tSLOT Pull-up (see Fig. 2) DS2482 pull-down Figure 7. Write-1 and Read-Data Time Slot Vcc tW1L tMSR VIH1 VIL1 0V tF1 tSLOT Pull-up (see Fig. 2) DS2482 pull-down 1-W Slave pull-down NOTE on Figure 7: Depending on its internal state, a 1-Wire slave device transmits data to its master (e.g., the DS2482-100).
PAGE 13
DS2482-100: Single-Channel 1-Wire Master 1-Wire Read Byte Command Code Command Parameter Description Typical Use Restriction Error Response Command Duration 1-Wire Activity Read Pointer Position Status Bits Affected Configuration Bits Affected 96h None Generates eight read-data time slots on the 1-Wire line and stores result in the Read Data register.
PAGE 14
DS2482-100: Single-Channel 1-Wire Master I2C INTERFACE General Characteristics The I²C bus uses a data line (SDA) plus a clock signal (SCL) for communication. Both SDA and SCL are bidirectional lines, connected to a positive supply voltage through a pullup resistor. When there is no communication, both lines are HIGH. The output stages of devices connected to the bus must have an open-drain or open-collector to perform the wired-AND function.
PAGE 15
DS2482-100: Single-Channel 1-Wire Master I2C Definitions The following terminology is commonly used to describe I2C data transfers. The timing references are defined in Figure 10. Figure 10. I²C Timing Diagram SDA tBUF tHD:STA tF tLOW tSP SCL tHD:STA tR tSU:STA tHIGH tHD:DAT STOP START Spike Suppression tSU:STO tSU:DAT Repeated START NOTE: TIMING IS REFERENCED TO VILMAX AND VIHMIN. Bus Idle or Not Busy: Both SDA and SCL are inactive and in their logic HIGH states.
PAGE 16
DS2482-100: Single-Channel 1-Wire Master A slave device that is ready to communicate acknowledges at least its slave address. However, some time later the slave may refuse to accept data, e.g., because of an invalid command code or parameter. In this case the slave device does not acknowledge any of the bytes that it refuses and leaves SDA HIGH.
PAGE 17
DS2482-100: Single-Channel 1-Wire Master I²C Communication Examples Device Reset, e.g., After Power-Up S AD,0 A DRST A Sr AD,1 A A\ This example includes an optional read access to verify the success of the command. P Write Configuration, e.g., Before Starting 1-Wire Activity Case A: 1-Wire Idle (1WB = 0) S AD,0 A WCFG A A Sr AD,1 A This example includes an optional read access to verify the success of the command. A\ P Case B: 1-Wire Busy (1WB = 1) S AD,0 A WCFG A\ P The master s
PAGE 18
DS2482-100: Single-Channel 1-Wire Master 1-Wire Write Byte, e.g., to Send a Command Code to the 1-Wire Line Case A: 1-Wire idle (1WB = 0), No Busy Polling S AD,0 A 1WWB A 33h A P (Idle) 33h is the valid 1-Wire ROM function command for Read ROM. The idle time is needed for the 1-Wire function to complete. There is no data read back from the 1-Wire line with this command. Case B: 1-Wire Idle (1WB = 0), Busy Polling Until the 1-Wire Command is Completed.
PAGE 19
DS2482-100: Single-Channel 1-Wire Master 1-Wire Single Bit, e.g., to Generate a Single Time Slot on the 1-Wire Line Case A: 1-Wire Idle (1WB = 0), No Busy Polling S AD,0 A 1WSB A A P (Idle) S AD,1 A A\ P The idle time is needed for the 1-Wire function to complete. Then access the device in read mode to get the result from the 1-Wire single-bit command.
PAGE 20
DS2482-100: Single-Channel 1-Wire Master Figure 11. Application Schematic VCC Current Limiting Resistor *RP SDA SCL (I²C port) µC PCTLZ DS2482-100 AD0 AD1 IO VCC SDA SCL PCTLZ *Rt 1-Wire line 1-Wire Device #1 (with special power requirements) * Rt Line termination resistor, typically 100Ω RP I²C pull-up resistor, see Application Information for RP sizing.
PAGE 21
DS2482-100: Single-Channel 1-Wire Master Since a 885Ω pullup resistor, as would be required to meet the rise time specification at fast speed and 400pF bus capacitance, is lower than Rpmin at 5.5V, a different approach is necessary. The "Max. Load…" line in Figure 12 is generated by first calculating the minimum pullup resistor at any given operating voltage ("Minimum Rp" line) and then calculating the respective bus capacitance that yields a rise time of 300ns.
PAGE 22
DS2482-100: Single-Channel 1-Wire Master REVISION HISTORY REVISION DATE DESCRIPTION 061208 Updated the Features bullets. Updated the VIL1 and RWPU values in the Electrical Characteristics table. Minor corrections to Figure 1; updated the Detailed Description section to clarify information about the active pullup and strong pullup. Replaced the Strong Pullup (SPU) section description and replaced Figure 4. Removed timing inaccuracies in Figure 8.