INTEGRATED CIRCUITS PCA9542 2-channel I2C multiplexer and interrupt controller Product specification 1999 Oct 07 Philips Semiconductors Product specification 2-channel I2C multiplexer and interrupt controller FEATURES PCA9542 PIN CONFIGURATION • 1-of-2 bi-directional translating multiplexer • Channel selection via I2C bus • Operating supply voltage 2.5 to 3.6 V • Operating temperature range 0°C to 70°C • Power-up with all multiplexer channels deselected • 3 address pins, allowing up to 8 devices on the I2C bus • Low on resistance A0 1 14 VDD A1 2 13 SDA A2 3 12 SCL INT0 4 11 INT SD0 5 10 SC1 SC0 6 9 SD1 VSS 7 8 INT1 DESCRIPTION SW00475 The PCA9542 is a 1-of-2 bi-directional translating multiplexer, controlled via the I2C bus. The SCL/SDA upstream pair fans out to two SCx/SDx downstream pairs, or channels. Only one SCx/SDx channel is selected at a time, determined by the contents of the programmable control register. Two interrupt inputs, one for each of the SCx/SDx downstream pair, are provided. One interrupt output, which acts as an AND of the two interrupt inputs, is provided. All I/O pins are 5 V tolerant. PIN DESCRIPTION The pass gates of the multiplexer are constructed such that the VDD pin can be used to limit the maximum high voltage which will be passed by the PCA9542. This allows the use of different bus voltages on each SCx/SDx pair, so that 3.3 V parts can communicate with 5 V parts without any additional protection. External pull-up resistors can pull the bus up to the desired voltage level for this channel. PIN NUMBER SYMBOL 1 A0 Address input 0 2 A1 Address input 1 3 A2 Address input 2 4 INT0 Interrupt input 0 5 SD0 Serial data 0 6 SC0 Serial clock 0 7 VSS Supply ground 8 INT1 Interrupt input 1 9 SD1 Serial data 1 10 SC1 Serial clock 1 11 INT Interrupt output 12 SCL Serial clock line 13 SDA Serial data line 14 VDD Supply voltage FUNCTION ORDERING INFORMATION PACKAGES TEMPERATURE RANGE ORDER CODE DRAWING NUMBER 14-Pin Plastic TSSOP 0°C to +70°C PCA9542PW DH SOT402-1 1999 Oct 07 2 853–2177 22486 Philips Semiconductors Product specification 2-channel I2C multiplexer and interrupt controller PCA9542 BLOCK DIAGRAM SC0 SC1 SD0 SD1 VSS VDD POWER-ON RESET A0 SCL SDA INPUT FILTER I2C-BUS CONTROL A1 A2 INT[0–1] INT LOGIC INT SW00379 1999 Oct 07 3 Philips Semiconductors Product specification 2-channel I2C multiplexer and interrupt controller PCA9542 CHANNEL SELECTION INTERRUPT HANDLING A SC0x/SD0x downstream pair, or channel, is selected by the contents of the control register. This register is written after the PCA9542 has been addressed. The 3 LSBs of the control byte are used to determine which channel is to be selected. When a channel is selected, the channel will become active after a stop condition has been placed on the I2C bus. This ensures that all SCx/SDx lines will be in a HIGH state when the channel is made active, so that no false conditions are generated at the time of connection. The PCA9542 provides 2 interrupt inputs, one for each channel and one open drain interrupt output. When an interrupt is generated by any device, it will be detected by the PCA9542 and the interrupt output will be driven LOW. The channel need not be active for detection of the interrupt. A bit is also set in the control byte. CONTROL BYTE 7 6 5 4 3 2 1 0 SELECTED CHANNEL X X X X X 0 X X none X X X X X 1 0 0 0 (SC0/SD0) X X X X X 1 0 1 1 (SC1/SD1) Bits 4 – 5 of the control byte correspond to channels 0 – 1 of the PCA9542, respectively. Therefore, if an interrupt is generated by any device connected to channel 1, then bit 5 will be set in the control register. Likewise, an interrupt on any device connected to channel 0 would cause bit 4 of the control register to be set. The master can then address the PCA9542 and read the contents of the control byte to determine which channel contains the device generating the interrupt. The master can then reconfigure the PCA9542 to select this channel, and locate the device generating the interrupt and clear it. It should be noted that more than one device can be providing an interrupt on a channel, so it is up to the master to ensure that all devices on a channel are interrogated for an interrupt. CONTROL REGISTER 7 6 X X 5 4 INT1 INT0 Interrupt bits (read only) 3 2 1 0 X B2 B1 B0 Channel select bits (read/write) SW00477 POWER-ON RESET During power-up, the control register defaults to all zeroes causing all the channels to be deselected. 1999 Oct 07 4 7 6 5 4 3 2 1 0 INTERRUPTING CHANNEL 0 0 0 1 X X X X 0 (SC0/SD0) 0 0 1 0 X X X X 1 (SC1/SD1) Philips Semiconductors Product specification 2-channel I2C multiplexer and interrupt controller PCA9542 CHARACTERISTICS OF THE I2C-BUS Start and stop conditions The I2C-bus is for 2-way, 2-line communication between different ICs or modules. The two lines are a serial data line (SDA) and a serial clock line (SCL). Both lines must be connected to a positive supply via a pull-up resistor when connected to the output stages of a device. Data transfer may be initiated only when the bus is not busy. Both data and clock lines remain HIGH when the bus is not busy. A HIGH-to-LOW transition of the data line, while the clock is HIGH is defined as the start condition (S). A LOW-to-HIGH transition of the data line while the clock is HIGH is defined as the stop condition (P) (see Figure 2). Bit transfer System configuration One data bit is transferred during each clock pulse. The data on the SDA line must remain stable during the HIGH period of the clock pulse as changes in the data line at this time will be interpreted as control signals (see FIgure 1). A device generating a message is a transmitter: a device receiving is the receiver. The device that controls the message is the master and the devices which are controlled by the master are the slaves (see Figure 3). SDA SCL data line stable; data valid change of data allowed SW00363 Figure 1. Bit transfer SDA SDA SCL SCL S P START condition STOP condition SW00365 Figure 2. Definition of start and stop conditions SDA SCL MASTER TRANSMITTER/ RECEIVER SLAVE RECEIVER SLAVE TRANSMITTER/ RECEIVER MASTER TRANSMITTER MASTER TRANSMITTER/ RECEIVER I2C MULTIPLEXER SLAVE SW00366 Figure 3. System configuration 1999 Oct 07 5 Philips Semiconductors Product specification 2-channel I2C multiplexer and interrupt controller PCA9542 Acknowledge The number of data bytes transferred between the start and the stop conditions from transmitter to receiver is not limited. Each byte of eight bits is followed by one acknowledge bit. The acknowledge bit is a HIGH level put on the bus by the transmitter whereas the master generates an extra acknowledge related clock pulse. A slave receiver which is addressed must generate an acknowledge after the reception of each byte. Also a master must generate an acknowledge after the reception of each byte that has been clocked out of the slave transmitter. The device that acknowledges has to pull down the SDA line during the acknowledge clock pulse, so that the SDA line is stable LOW during the HIGH period of the acknowledge related clock pulse, set-up and hold times must be taken into account. A master receiver must signal an end of data to the transmitter by not generating an acknowledge on the last byte that has been clocked out of the slave. In this event, the transmitter must leave the data line HIGH to enable the master to generate a stop condition. DATA OUTPUT BY TRANSMITTER not acknowledge DATA OUTPUT BY RECEIVER acknowledge SCL FROM MASTER 1 2 8 9 S clock pulse for acknowledgement START condition SW00368 Figure 4. Acknowledgement on the I2C-bus slave address 1 1 1 0 A2 A1 A0 hardware selectable fixed SW00453 Figure 5. Slave address X SDA 1 SCL X 2 X 3 X 4 X X 5 6 X 7 X 8 X X 1 9 X 2 SLAVE ADDRESS SDA S 1 1 1 0 A2 X 3 X 4 X 5 X 6 X 7 8 9 CONTROL REGISTER A1 A0 start condition 0 X A R/W X INT1 INT0 X B2 acknowledge from slave B1 B0 A P acknowledge from slave PREVIOUS CHANNEL NEW CHANNEL tpv SW00480 Figure 6. WRITE control register CONTROL REGISTER SLAVE ADDRESS SDA S 1 1 start condition 1 0 A2 A1 A0 1 R/W X A X INT1 INT0 X acknowledge from slave B2 last byte B1 B0 NA no acknowledge from master P stop condition SW00481 Figure 7. READ control register 1999 Oct 07 6 Philips Semiconductors Product specification 2-channel I2C multiplexer and interrupt controller PCA9542 ABSOLUTE MAXIMUM RATINGS1, 2 In accordance with the Absolute Maximum Rating System (IEC 134).Voltages are referenced to GND (ground = 0 V). RATING UNIT DC supply voltage –0.5 to +7.0 V VI DC input voltage –0.5 to +7.0 V II DC input current ±20 mA SYMBOL VDD PARAMETER CONDITIONS IO DC output current ±25 mA IDD Supply current ±100 mA ISS Supply current ±100 mA Ptot total power dissipation Tstg Storage temperature range Tamb Operating ambient temperature 400 mW –60 to +150 °C 0 to +70 °C NOTES: 1. Stresses beyond those listed 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. 2. The performance capability of a high-performance integrated circuit in conjunction with its thermal environment can create junction temperatures which are detrimental to reliability. The maximum junction temperature of this integrated circuit should not exceed 150°C. DC CHARACTERISTICS VDD = 2.5 to 3.6 V; VSS = 0 V; Tamb = 0°C to +70°C; unless otherwise specified. SYMBOL PARAMETER TEST CONDITIONS LIMITS MIN TYP MAX UNIT Supply VDDQn ≤ VDD Supply voltage IDD Supply current Istb Standby current VPOR Power-on reset voltage 2.5 3.6 V 20 100 µA – 2.5 100 µA – 1.3 2.1 V Operating mode; VDD = 3.6 V; no load; VI = VDD or VSS; fSCL = 100 kHz – Standby mode; VDD = 3.6 V; no load; VI = VDD or VSS VDD = 3.6 V; no load; VI = VDD or VSS Input SCL; input/output SDA VIL LOW level input voltage –0.5 – 0.3 VDD V VIH HIGH level input voltage 0.7 VDD – 6 V VOL = 0.4 V 3 – – VOL = 0.6 V 6 – – VI = VDD or VSS –1 – +1 µA VI = VSS – – 10 pF –0.5 – +0.3 VDD V IOL LOW level out output ut current IL Leakage current Ci Input capacitance mA Select inputs A0 to A2 / INT0 to INT3 VIL LOW level input voltage VIH HIGH level input voltage ILI Input leakage current 0.7 VDD – VDD + 0.5 V pin at VDD or VSS –1 – +1 µA VCC = 3.67 V, VO = 0.4 V, IO = 15 mA 5 20 30 VCC = 2.3 to 2.7 V, VO = 0.4V, IO = 10 mA 7 26 55 Ω Pass Gate RON Switch resistance Vswin = VDD = 3.3 V; Iswout = –100 µA VPass P IL Switch output out ut voltage Leakage current Vswin = VDD = 3.0 to 3.6 V; Iswout = –100 µA 2.2 1.6 Vswin = VDD = 2.5 V; Iswout = –100 µA 2.8 1.5 Vswin = VDD = 2.3 to 2.7 V; Iswout = –100 µA 1.1 VI = VDD or VSS –1 – VOL = 0.4 V 3 VI = VDD or VSS –1 V 2.0 +1 µA – – mA – +1 µA INT Output IOL IL 1999 Oct 07 LOW level output current Leakage current 7 Philips Semiconductors Product specification 2-channel I2C multiplexer and interrupt controller PCA9542 AC CHARACTERISTICS SYMBOL STANDARD-MODE I2C-BUS PARAMETER MIN tpd MAX SCL clock frequency tBUF MIN UNIT MAX 0.31 Propagation delay from SDA to SDn or SCL to SCn fSCL FAST-MODE I2C-BUS 0.31 ns 0 100 0 400 KHz Bus free time between a STOP and START condition 4.7 – 1.3 – µs Hold time (repeated) START condition After this period, the first clock pulse is generated 4.0 – 0.6 – µs tLOW LOW period of the SCL clock 4.7 – 1.3 – µs tHIGH HIGH period of the SCL clock 4.0 – 0.6 – µs tSU:STA Set-up time for a repeated START condition 4.7 – 0.6 tHD:DAT Data hold time: for CBUS compatible masters for I2C-bus devices 5.0 02 – – – 02 tSU:DAT Data set-up time 250 – 1004 tHD:STA tSU:STO µs – 0.93 µs µs – ns 5 300 ns Set-up time for STOP condition – 1000 20 + 0.1Cb tr Rise time of both SDA and SCL signals – 300 20 + 0.1Cb5 300 ns tf Fall time of both SDA and SCL signals 4.0 – 0.6 – µs 400 – 400 pF Cb Capacitive load for each bus line INT tiv INTn to INT active valid time 4 4 µs tir INTn to INT inactive delay time 2 2 µs Lpwr LOW level pulse width rejection or INTn inputs 1 1 ns Hpwr HIGH level pulse width rejection or INTn inputs 500 500 ns NOTES: 1. Pass gate propagation delay is calculated from the 20 Ω typical RON and and the 15 pF load capacitance. 2. A device must internally provide a hold time of at least 300 ns for the SDA signal (referred to the VIHmin of the SCL signal) in order to bridge the undefined region of the falling edge of SCL. 3. The maximum tHD:DAT has only to be met if the device does not stretch the LOW period (tLOW) of the SCL signal. 4. A fast-mode I2C bus device can be used in a standard-mode I2C-bus system, but the requirement tSU:DAT ≥ 250 ns must then be met. This will automatically be the case if the device does not stretch the LOW period of the SCL signal. If such a device does stretch the LOW period of the SCL signal, it must output the next data bit to the SDA line trmax + tSU:DAT = 1000 + 250 = 1250 ns (according to the standard-mode I2C-bus specification) before the SCL line is released. 5. Cb = total capacitance of one bus line in pF. SDA tBUF tLOW tR tF tHD;STA tSP SCL tHD;STA P S tSU;STA tHD;DAT tHIGH tSU;DAT Sr tSU;STO P SU00645 Figure 8. Definition of timing on the I2C-bus 1999 Oct 07 8 Philips Semiconductors Product specification 2-channel I2C multiplexer and interrupt controller TSSOP20: plastic thin shrink small outline package; 20 leads; body width 4.4 mm 1999 Oct 07 9 PCA9542 SOT360-1 Philips Semiconductors Product specification 2-channel I2C multiplexer and interrupt controller PCA9542 Purchase of Philips I2C components conveys a license under the Philips’ I2C patent to use the components in the I2C system provided the system conforms to the I2C specifications defined by Philips. This specification can be ordered using the code 9398 393 40011. Data sheet status Data sheet status Product status Definition [1] Objective specification Development This data sheet contains the design target or goal specifications for product development. Specification may change in any manner without notice. Preliminary specification Qualification This data sheet contains preliminary data, and supplementary data will be published at a later date. Philips Semiconductors reserves the right to make changes at any time without notice in order to improve design and supply the best possible product. Product specification Production This data sheet contains final specifications. Philips Semiconductors reserves the right to make changes at any time without notice in order to improve design and supply the best possible product. [1] Please consult the most recently issued datasheet before initiating or completing a design. Definitions Short-form specification — The data in a short-form specification is extracted from a full data sheet with the same type number and title. For detailed information see the relevant data sheet or data handbook. Limiting values definition — Limiting values given are in accordance with the Absolute Maximum Rating System (IEC 134). Stress above one or more of the limiting values may cause permanent damage to the device. These are stress ratings only and operation of the device at these or at any other conditions above those given in the Characteristics sections of the specification is not implied. Exposure to limiting values for extended periods may affect device reliability. Application information — Applications that are described herein for any of these products are for illustrative purposes only. Philips Semiconductors make no representation or warranty that such applications will be suitable for the specified use without further testing or modification. Disclaimers Life support — These products are not designed for use in life support appliances, devices or systems where malfunction of these products can reasonably be expected to result in personal injury. Philips Semiconductors customers using or selling these products for use in such applications do so at their own risk and agree to fully indemnify Philips Semiconductors for any damages resulting from such application. Right to make changes — Philips Semiconductors reserves the right to make changes, without notice, in the products, including circuits, standard cells, and/or software, described or contained herein in order to improve design and/or performance. Philips Semiconductors assumes no responsibility or liability for the use of any of these products, conveys no license or title under any patent, copyright, or mask work right to these products, and makes no representations or warranties that these products are free from patent, copyright, or mask work right infringement, unless otherwise specified. Copyright Philips Electronics North America Corporation 1999 All rights reserved. Printed in U.S.A. Philips Semiconductors 811 East Arques Avenue P.O. Box 3409 Sunnyvale, California 94088–3409 Telephone 800-234-7381 Date of release: 10-99 Document order number: 1999 Oct 07 10 9397–750–06496