DS2408 1-Wire 8-Channel Addressable Switch BENEFITS AND FEATURES PIN CONFIGURATION Control Eight Independent I/O Port Pins from a Single Micro Port Pin o Eight Channels of Programmable I/O with Open-Drain Outputs o On-Resistance of PIO Pulldown Transistor 100 (max) Off-Resistance 10M (typ) o Individual Activity Latches Capture Asynchronous State Changes at PIO Inputs for Interrogation by the Bus Master o Data-Strobe Output to Synchronize PIO Logic States to External Read/Write Circuitry Minimalist 1-Wire Interface Lowers Cost and 150-mil SO Interface Complexity o Built-in Multidrop Controller Ensures Compatibility with Other 1-Wire Net Products ORDERING INFORMATION o Supports 1-Wire Conditional Search Command with Response Controlled by Programmable PIO PART TEMP RANGE PIN-PACKAGE Conditions DS2408S+ -40C to +85C 16 SO o Unique Factory-Lasered 64-Bit Registration DS2408S+T&R -40C to +85C 16 SO Number Ensures Error-Free Device Selection and +Denotes a lead(Pb)-free package. Absolute Part Identity T&R = Tape and reel. o Communicates to Host with a Single Digital Signal at 15.3kbps or 100kbps Wide Voltage and Temperature Operating Ranges Enables Robust System Performance o 2.8V to 5.25V o -40C to +85C Industrial Temperature Range DESCRIPTION The DS2408 is an 8-channel, programmable I/O 1-Wire chip. PIO outputs are configured as open-drain and provide an on resistance of 100 max. A robust PIO channel-access communication protocol ensures that PIO output-setting changes occur error-free. A data-valid strobe output can be used to latch PIO logic states into external circuitry such as a D/A converter (DAC) or microcontroller data bus. DS2408 operation is controlled over the single-conductor 1-Wire bus. Device communication follows the standard Dallas Semiconductor 1-Wire protocol. Each DS2408 has its own unalterable and unique 64-bit ROM registration number that is factory lasered into the chip. The registration number guarantees unique identification and is used to address the device in a multidrop 1-Wire net environment. Multiple DS2408 devices can reside on a common 1-Wire bus and can operate independently of each other. The DS2408 also supports 1-Wire conditional search capability based on PIO conditions or power-on-reset activity the conditions to cause participation in the conditional search are programmable. The DS2408 has an optional V CC supply connection. When an external supply is absent, device power is supplied parasitically from the 1-Wire bus. When an external supply is present, PIO states are maintained in the absence of the 1-Wire bus power source. The RSTZ signal is configurable to serve as either a hard-wired reset for the PIO output or as a strobe for external circuitry to indicate that a PIO write or PIO read has completed. 1-Wire is a registered trademark of Maxim Integrated Products, Inc. 1 of 39 19-5702 3/15 DS2408 ABSOLUTE MAXIMUM RATINGS* P0 to P7, RSTZ, I/O Voltage to GND -0.5V, +6V P0 to P7, RSTZ, I/O combined sink current 20mA Operating Temperature Range -40C to +85C Junction Temperature +150C Storage Temperature Range -55C to +125C Lead temperature (soldering 10s) +300C Soldering Temperature (reflow) +260C * This is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operation sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods of time may affect reliability. ELECTRICAL CHARACTERISTICS (V = 0V or V , T = -40C or +85C.) CC PUP A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS 1-Wire Pullup Standard speed 2.8 5.25 V V PUP Voltage Overdrive speed 3.3 5.25 Standby Supply V at V CC PUP, I 1 A CCS Current I/O pin at 0.3V I/O Pin General Data 1-Wire Pullup R (Notes 1, 2) 2.2 k PUP Resistance Input Capacitance C (Notes 3, 4) 1200 pF IO I/O pin at V PUP, Input Load Current I 1 A L V at 0V CC High-to-Low V (Notes 4, 5, 6) 0.5 3.2 V TL Switching Threshold Input-Low Voltage V (Notes 1, 7) 0.30 V IL Low-to-High V (Notes 4, 5, 8) 0.8 3.4 V TH Switching Threshold Switching Hysteresis V (Notes 9, 4) 0.16 0.73 V HY Output-Low Voltage V (Note 10) 0.4 V OL at 4mA Standard speed, R = PUP 5 2.2k Overdrive speed, R = PUP Recovery Time 2 t s 2.2k REC (Note 1) Overdrive speed, Directly prior to reset pulse R 5 PUP = 2.2k Rising-Edge Hold-off Standard speed 0.5 5 t s REH Time (Notes 11, 4) Overdrive speed 0.5 2 Timeslot Duration Standard speed 65 t s SLOT (Notes 1, 12) Overdrive speed 10 2 of 39