PCA9601D

PCA9601 Dual bidirectional bus buffer Rev. 2 — 6 May 2011 Product data sheet 1. General description The PCA9601 is designed to isolate I2C-bus capacitance, allowing long buses to be driven in point-to-point or multipoint applications of up to 4000 pF. The PCA9601 is a higher-speed version of the P82B96 and a higher drive version of the PCA9600 that allows many more Fast-mode Plus (Fm+) slaves on remote daughter cards in applications with temperature range of 0 °C to 85 °C. It creates a non-latching, bidirectional, logic interface between a normal I2C-bus and a range of other higher capacitance or different voltage bus configurations. It can operate at speeds up to at least 1 MHz, and the high drive side is compatible with the Fast-mode Plus specifications. The PCA9601 features temperature-stabilized logic voltage levels at its SX/SY interface making it suitable for interfacing with buses that have non I2C-bus-compliant logic levels such as SMBus, PMBus, or with microprocessors that use those same TTL logic levels. 15 mA drive capability over 0 °C to 85 °C at SX/SY allows driving a 5 V Fm+ bus with 470 pF loading. The separation of the bidirectional I2C-bus signals into unidirectional TX and RX signals enables the SDA and SCL signals to be transmitted via balanced transmission lines (twisted pairs), or with galvanic isolation using opto or magnetic coupling. The TX and RX signals may be connected together to provide a normal bidirectional signal. 2. Features and benefits Bidirectional data transfer of I2C-bus signals 15 mA SX/SY sink capability yields 5 V Fm+ bus rise time with 470 pF loads Isolates capacitance allowing > 400 pF on SX/SY side and 4000 pF on TX/TY side 1 MHz operation on up to 20 meters of wire (see AN10658) Supply voltage range of 2.5 V to 15 V with I2C-bus logic levels on SX/SY side independent of supply voltage Splits I2C-bus signal into pairs of forward/reverse TX/RX, TY/RY signals for interface with opto-electrical isolators and similar devices that need unidirectional input and output signal paths Low power supply current ESD protection exceeds 4500 V HBM per JESD22-A114, and 1400 V CDM per JESD22-C101 Latch-up testing is done to JEDEC Standard JESD78 which exceeds 100 mA Packages offered: SO8 and TSSOP8 (MSOP8) NXP Semiconductors PCA9601 Dual bidirectional bus buffer 3. Applications Interface between I2C-buses operating at different logic levels (for example, 5 V and 3 V or 15 V) Interface between I2C-bus and SMBus (350 μA) standard or Fm+ standard Simple conversion of I2C-bus SDA or SCL signals to multi-drop differential bus hardware, for example, via compatible PCA82C250 Interfaces with opto-couplers to provide opto-isolation between I2C-bus nodes up to 1 MHz Long distance point-to-point or multipoint architectures 4. Ordering information Table 1. Ordering information Package Name PCA9601D PCA9601DP SO8 TSSOP8 Description plastic small outline package; 8 leads; body width 3.9 mm plastic thin shrink small outline package; 8 leads; body width 3 mm Version SOT96-1 SOT505-1 Type number 4.1 Ordering options Table 2. PCA9601D PCA9601DP Ordering options Topside mark PCA9601 9601 Temperature range −40 °C to +85 °C −40 °C to +85 °C Type number 5. Block diagram VCC (2.5 V to 15 V) 8 PCA9601 SX (SDA) static level offset card side SY (SCL) 1 3 2 7 5 6 4 GND 002aae873 TX (TxD, SDA) RX (RxD, SDA) TY (TxD, SCL) RY (RxD, SCL) higher drive, longer distance side Fig 1. Block diagram of PCA9601 PCA9601 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved. Product data sheet Rev. 2 — 6 May 2011 2 of 32 NXP Semiconductors PCA9601 Dual bidirectional bus buffer 6. Pinning information 6.1 Pinning SX RX TX GND 1 2 8 7 VCC SY RY TY SX RX TX GND 1 2 3 4 002aae875 8 7 VCC SY RY TY PCA9601D 3 4 002aae874 6 5 PCA9601DP 6 5 Fig 2. Pin configuration for SO8 Fig 3. Pin configuration for TSSOP8 (MSOP8) 6.2 Pin description Table 3. Symbol SX RX TX GND TY RY SY VCC Pin description Pin 1 2 3 4 5 6 7 8 Description I2C-bus (SDA or SCL) receive signal transmit signal negative supply voltage transmit signal receive signal I2C-bus (SDA or SCL) positive supply voltage PCA9601 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved. Product data sheet Rev. 2 — 6 May 2011 3 of 32 NXP Semiconductors PCA9601 Dual bidirectional bus buffer 7. Functional description Refer to Figure 1 “Block diagram of PCA9601”. The PCA9601 has two identical buffers allowing buffering of SDA and SCL I2C-bus signals. Each buffer is made up of two logic signal paths, a forward path from the I2C-bus interface, pins SX and SY which drive the buffered bus, and a reverse signal path from the buffered bus input, pins RX and RY to drive the I2C-bus interface. These paths: • sense the voltage state of I2C-bus pins SX (and SY) and transmit this state to pin TX (and TY respectively), and • sense the state of pins RX and RY and pull the I2C-bus pin LOW whenever pin RX or pin RY is LOW. The rest of this discussion will address only the ‘X’ side of the buffer; the ‘Y’ side is identical. 7.1 Static level offset card side The I2C-bus pin SX is specified to allow interfacing with Fast-mode, Fm+ and TTL-based systems. The logic threshold voltage levels at SX on this I2C-bus are independent of the IC supply voltage VCC. The maximum I2C-bus supply voltage is 15 V. 7.1.1 Fast-mode operation When interfacing with Fast-mode systems, the SX pin is guaranteed to sink the normal 3 mA with a VOL of 0.74 V maximum. That guarantees compliance with the Fast-mode I2C-bus specification for all I2C-bus voltages greater than 3 V, as well as compliance with SMBus or other systems that use TTL switching levels. SX is guaranteed to sink an external 3 mA in addition to its internally sourced pull-up of typically 300 μA (maximum 1 mA at −40 °C). When selecting the pull-up for the bus at SX, the sink capability of other connected drivers should be taken into account. Most TTL devices are specified to sink at least 4 mA so then the pull-up is limited to 3 mA by the requirement to ensure the 0.8 V TTL LOW. For Fast-mode I2C-bus operation, the other connected I2C-bus parts may have the minimum sink capability of 3 mA. SX sources typically 300 μA (maximum 1 mA at −40 °C), which forms part of the external driver loading. When selecting the pull-up it is necessary to subtract the SX pin pull-up current, so, worst-case at −40 °C, the allowed pull-up can be limited (by external drivers) to 2 mA. 7.1.2 Fast-mode Plus operation When the interface at SX is an Fm+ bus with a voltage greater than 4 V, its higher specified sink capability may be used. PCA9601 has a guaranteed sink capability of 15 mA at VOL = 1 V maximum over 0 °C to 85 °C. That 1 V complies with the bus LOW requirement (0.25Vbus) of any Fm+ bus operating at 4 V or greater. Since the other connected Fm+ devices have a drive capability greater than 20 mA, the pull-up may be selected for 15 mA sink current at VOL = 1 V. For a nominal 5 V bus (5.5 V maximum) the allowed pull-up is (5.5 V − 1 V) / 15 mA = 300 Ω. With 300 Ω pull-up, the Fm+ rise time of 120 ns maximum can be met with total bus loading up to 470 pF. PCA9601 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved. Product data sheet Rev. 2 — 6 May 2011 4 of 32 NXP Semiconductors PCA9601 Dual bidirectional bus buffer 7.2 High drive, long distance side The logic level on RX is determined from the power supply voltage VCC of the chip. Logic LOW is below 40 % of VCC, and logic HIGH is above 55 % of VCC (with a typical switching threshold just slightly below half VCC). TX is an open-collector output without ESD protection diodes to VCC. It may be connected via a pull-up resistor to a supply voltage in excess of VCC, as long as the 15 V rating is not exceeded. It has a larger current sinking capability than a normal I2C-bus device, being able to sink a static current of greater than 30 mA, and typical 100 mA dynamic pull-down capability as well. A logic LOW is transmitted to TX when the voltage at I2C-bus pin SX is below 0.425 V. A logic LOW at RX will cause I2C-bus pin SX to be pulled to a logic LOW level in accordance with I2C-bus requirements (maximum 1.5 V in 5 V applications) but not low enough to be looped back to the TX output and cause the buffer to latch LOW. The LOW level this chip can achieve on the I2C-bus by a LOW at RX is typically 0.64 V when sinking 1 mA. If the supply voltage VCC fails, then neither the I2C-bus nor the TX output will be held LOW. Their open-collector configuration allows them to be pulled up to the rated maximum of 15 V even without VCC present. The input configuration on SX and RX also presents no loading of external signals when VCC is not present. The effective input capacitance of any signal pin, measured by its effect on bus rise times, is less than 10 pF for all bus voltages and supply voltages including VCC = 0 V. 7.3 Connections to other bus buffers Two or more SX or SY I/Os must not be interconnected. The PCA9601 design does not support this configuration. Bidirectional I2C-bus signals do not allow any direction control pin so, instead, slightly different logic LOW voltage levels are used at SX/SY to avoid latching of this buffer. A ‘regular I2C-bus LOW’ applied at the RX/RY of a PCA9601 will be propagated to SX/SY as a ‘buffered LOW’ with a slightly higher voltage level. If this special ‘buffered LOW’ is applied to the SX/SY of another PCA9601, that second PCA9601 will not recognize it as a ‘regular I2C-bus LOW’ and will not propagate it to its TX/TY output. The SX/SY side of PCA9601 may not be connected to similar buffers that rely on special logic thresholds for their operation, for example P82B96, PCA9511A, PCA9515A, ‘B’ side of PCA9517, etc. The SX/SY side is only intended for, and compatible with, the normal I2C-bus logic voltage levels of I2C-bus master and slave chips, or even TX/RX signals of a second PCA9601 or P82B96 if required. The TX/RX and TY/RY I/O pins use the standard I2C-bus logic voltage levels of all I2C-bus parts. There are no restrictions on the interconnection of the TX/RX and TY/RY I/O pins to other PCA9601s, for example in a star or multipoint configuration with the TX/RX and TY/RY I/O pins on the common bus and the SX/SY side connected to the line card slave devices. For more details see Application Note AN10658, “Sending I2C-bus signals via long communication cables”. PCA9601 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved. Product data sheet Rev. 2 — 6 May 2011 5 of 32 NXP Semiconductors PCA9601 Dual bidirectional bus buffer 7.4 Comparison of PCA9601/PCA9600 and P82B96 The PCA9601 is a direct upgrade of the P82B96 with the significant differences summarized in Table 4. The PCA9601 provides improved interface to the higher drive Fast-mode Plus devices on the SX/SY sides. Table 4. Detail Supply voltage (VCC) range: Maximum operating bus voltage (independent of VCC): Typical operating supply current: Typical LOW-level input voltage on (SX/SY side): I2C-bus PCA9601/PCA9600 versus P82B96 PCA9601/PCA9600 2.5 V to 15 V 15 V 5 mA 0.5 V over −40 °C to +85 °C 0.74 V (max.) over −40 °C to +85 °C 1 V (max.) over 0 °C to 85 °C (PCA9601 only) 0 mV/°C I2C-bus P82B96 2 V to 15 V 15 V 1 mA 0.65 V at 25 °C 0.88 V (typ.) at 25 °C n/a −2 mV/°C LOW-level output voltage on I2C-bus (SX/SY side; 3 mA sink): LOW-level output voltage on Fm+ I2C-bus (SX/SY side; 15 mA sink): Temperature coefficient of VIL / VOL: Logic voltage levels on SX/SY bus (independent of VCC): Typical propagation delays: TX/RX switching specifications (I2C-bus compliant): RX logic levels with tighter control than I2C-bus limit of 30 % to 70 %: Maximum bus speed: ESD rating HBM per JESD22-A114: Package: compatible with and similar compatible with I2C-bus and similar buses using TTL levels (SMBus, etc.) buses using TTL levels (SMBus, etc.) < 100 ns < 200 ns yes, all classes including 1 MHz Fm+ yes, all classes including Fm+ yes, 40 % to 55 % (48 % nominal) > 1 MHz > 4500 V SO8, TSSOP8 (MSOP8) yes, 42 % to 58 % (50 % nominal) > 400 kHz > 3500 V DIP8, SO8, TSSOP8 (MSOP8) When the device driving the PCA9601/PCA9600 is an I2C-bus compatible device, then the PCA9601 is an improvement on the P82B96 as shown in Table 4. There will always be exceptions however, and if the device driving the bus buffer is not I2C-bus compatible (e.g., you need to use the micro already in the system and bit-bang using two GPIO pins) then here are some considerations that would point to using the P82B96 instead: • When the pull-up must be the weakest one possible. The spec is 200 μA for P82B96, but it typically works even below that. And if designing for a temperature range −40 °C up to +60 °C, then the driver when sinking 200 μA only needs to drive a guaranteed low of 0.55 V. For the PCA9601/PCA9600, over that same temperature range and when sinking 1.3 mA (at −40 °C), the device driving the bus buffer must provide the required low of 0.425 V. • When the lower operating temperature range is restricted (say 0 °C). The P82B96 larger SX voltage levels then make a better typical match with the driver, even when the supply is as low as 3.3 V. For an I2C-bus compliant driver on 3.3 V the P82B96 is required to guarantee a bus low that is below 0.83 V. P82B96 guarantees that with a 200 μA pull-up. PCA9601 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved. Product data sheet Rev. 2 — 6 May 2011 6 of 32 NXP Semiconductors PCA9601 Dual bidirectional bus buffer • When the operating temperature range is restricted at both limits. An I2C driver's typical output is well below 0.4 V and the P82B96 typically requires 0.6 V input even at +60 °C, so there is a reasonable margin. The PCA9601/PCA9600 requires a typical input low of 0.5 V so its typical margin is smaller. At 0 °C the driver requires a typical input low of 1.16 V and P82B96 provides 0.75 V, so again the typical margin is already quite big and even though PCA9601/PCA9600 is better, providing 0.7 V, that difference is not big. 8. Limiting values Table 5. Limiting values In accordance with the Absolute Maximum Rating System (IEC 60134). Voltages with respect to pin GND. Symbol VCC VI2C-bus VO VI II2C-bus Ptot Tj Tstg Tamb [1] Parameter supply voltage I2C-bus voltage Conditions VCC to GND SX and SY; I2C-bus SDA or SCL TX and TY; buffered output RX and RY; receive input SX and SY; I2C-bus SDA or SCL operating range operating [1] Min −0.3 −0.3 −0.3 −0.3 −40 −55 −40 Max +18 +18 +18 +18 250 300 +125 +125 +85 Unit V V V V mA mW °C °C °C output voltage input voltage I2C-bus current total power dissipation junction temperature storage temperature ambient temperature [1] See also Section 10.2 “Negative undershoot below absolute minimum value”. PCA9601 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved. Product data sheet Rev. 2 — 6 May 2011 7 of 32 NXP Semiconductors PCA9601 Dual bidirectional bus buffer 9. Characteristics Table 6. Characteristics Tamb = −40 °C to +85 °C unless otherwise specified; voltages are specified with respect to GND with VCC = 2.5 V to 15 V unless otherwise specified. Typical values are measured at VCC = 5 V and Tamb = 25 °C. Symbol Parameter Power supply VCC ICC ΔICC supply voltage supply current additional supply current operating VCC = 5 V; buses HIGH VCC = 15 V; buses HIGH per TX/TY output driven LOW; VCC = 5.5 V 2.5 5.2 5.5 1.4 15 6.75 7.3 3.0 V mA mA mA Conditions Min Typ Max Unit Bus pull-up (load) voltages and currents Pins SX and SY; I2C-bus VI VO IO IO(sink) IL VO Iload input voltage output voltage output current output sink current leakage current output voltage load current open-collector; RX and RY HIGH open-collector; RX and RY HIGH static; VSX = VSY = 0.4 V VSX = VSY = 1 V; RX and RY LOW; Tamb = 0 °C to 85 °C VSX = VSY = 15 V; RX and RY HIGH open-collector maximum recommended on buffered bus; VTX = VTY = 0.4 V; SX and SY LOW on I2C-bus = 0.4 V from buffered bus; VTX = VTY = 1 V; SX and SY LOW on I2C-bus = 0.4 V on buffered bus; VTX = VTY = VCC = 15 V; SX and SY HIGH from I2C-bus on SX and SY RX and RY HIGH or LOW; SX and SY LOW ≤ 1 V RX and RY HIGH; SX and SY HIGH > 1.4 V from buffered bus on RX and RY; SX and SY HIGH or LOW; VRX = VRY = 0.4 V IL leakage current on buffered bus input on RX and RY; VRX = VRY = 15 V [1] [1] 0.3 15 - - 15 15 15 10 15 30 V V mA mA μA V mA Pins TX and TY IO IL output current leakage current 60 - 130 - 10 mA μA Input currents II input current −0.3 −1.5 −1 10 −10 mA μA μA [1] [2] - - 10 μA PCA9601 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved. Product data sheet Rev. 2 — 6 May 2011 8 of 32 NXP Semiconductors PCA9601 Dual bidirectional bus buffer Table 6. Characteristics …continued Tamb = −40 °C to +85 °C unless otherwise specified; voltages are specified with respect to GND with VCC = 2.5 V to 15 V unless otherwise specified. Typical values are measured at VCC = 5 V and Tamb = 25 °C. Symbol Parameter Output logic LOW level Pins SX and SY VOL LOW-level output voltage on Standard-mode or Fast-mode I2C-bus ISX = ISY = 3 mA; Figure 6 ISX = ISY = 0.3 mA; Figure 5 on 5 V Fm+ I2C-bus ISX = ISY = 15 mA; Tamb = 0 °C to 85 °C ΔV/ΔT voltage variation with temperature ISX = ISY = 0.3 mA to 3 mA 0.85 0 1 V %/K 0.7 0.6 0.74 0.65 V V Conditions Min Typ Max Unit Input logic switching threshold voltages Pins SX and SY VIL Vth(IH) ΔV/ΔT LOW-level input voltage HIGH-level input threshold voltage voltage variation with temperature HIGH-level input voltage input threshold voltage LOW-level input voltage voltage difference fraction of applied VCC fraction of applied VCC fraction of applied VCC SX and SY; SX output LOW at 0.3 mA to SX input HIGH maximum SX, SY, TX and TY; voltage at which all buses are to be released at 25 °C Figure 9 [4] on normal I2C-bus; Figure 7 on normal I2C-bus; Figure 8 [3] 580 - 0 425 - mV mV %/K Pins RX and RY VIH Vth(i) VIL ΔV 0.55VCC 50 0.4VCC V V V mV 0.48VCC - Logic level threshold difference Bus release on VCC failure VCC ΔV/ΔT supply voltage voltage variation with temperature −4 1 V %/K PCA9601 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved. Product data sheet Rev. 2 — 6 May 2011 9 of 32 NXP Semiconductors PCA9601 Dual bidirectional bus buffer Table 6. Characteristics …continued Tamb = −40 °C to +85 °C unless otherwise specified; voltages are specified with respect to GND with VCC = 2.5 V to 15 V unless otherwise specified. Typical values are measured at VCC = 5 V and Tamb = 25 °C. Symbol Parameter Buffer response td time[5] VSX to VTX, VSY to VTY; on falling input between VSX = input switching threshold, and VTX output falling to 50 % VCC VSX to VTX, VSY to VTY; on rising input between VSX = input switching threshold, and VTX output reaching 50 % VCC VRX to VSX, VRY to VSY; on falling input between VRX = input switching threshold, and VSX output falling to 50 % VCC VRX to VSX, VRY to VSY; on rising input between VRX = input switching threshold, and VSX output reaching 50 % VCC Input capacitance Ci input capacitance effective input capacitance of any signal pin measured by incremental bus rise times; guaranteed by design, not production tested 10 pF 50 ns Conditions Min Typ Max Unit VCC = 5 V; pin TX pull-up resistor = 160 Ω; pin SX pull-up resistor = 2.2 kΩ; no capacitive load delay time - 60 - ns - 100 - ns - 95 - ns [1] This bus pull-up current specification is intended to assist design of the bus pull-up resistor. It is not a specification of the sink capability (see VOL under sub-section “Output logic LOW level”). When used on an Fm+ bus the load current is limited to 15 mA by the drive capability of PCA9601. When used in a standard I2C-bus the load current is limited by the drive capability of other devices on the bus. The maximum static sink current for a Standard/Fast-mode I2C-bus is 3 mA and PCA9601 is guaranteed to sink more than 3 mA at SX/SY when its pins are holding the bus LOW. However, when an external device pulls the SX/SY pins below 1.4 V, the PCA9601 will source a current between 0 mA and 1 mA maximum. When that other external device is driving LOW it will pull the bus connected to SX or SY down to, or below, the 0.4 V level referenced in the I2C-bus specification and in these test conditions. Then that device must be able to sink up to 1 mA coming from SX/SY plus the usual pull-up current. Therefore in Standard and Fast-mode systems the external pull-up used at SX/SY should be limited to 2 mA. The typical and maximum currents sourced by SX/SY as a function of junction temperature are shown in Figure 10, and the equivalent circuit at the SX/SY interface is shown in Figure 4. Valid over temperature for VCC ≤ 5 V. At higher VCC, this current may increase to maximum −20 μA at VCC = 15 V. The input logic threshold is independent of the supply voltage. The minimum value requirement for pull-up current, 0.3 mA, guarantees that the minimum value for VSX output LOW will always exceed the maximum VSX input HIGH level to eliminate any possibility of latching. The specified difference is guaranteed by design within any IC. While the tolerances on absolute levels allow a small probability, the LOW from one SX output is recognized by an SX input of another PCA9601, this has no consequences for normal applications. In any design the SX pins of different ICs should never be linked because the resulting system would be very susceptible to induced noise and would not support all I2C-bus operating modes. The fall time of VTX from 5 V to 2.5 V in the test is approximately 10 ns. The fall time of VSX from 5 V to 2.5 V in the test is approximately 20 ns. The rise time of VTX from 0 V to 2.5 V in the test is approximately 15 ns. The rise time of VSX from 0.7 V to 2.5 V in the test is approximately 25 ns. [2] [3] [4] [5] PCA9601 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved. Product data sheet Rev. 2 — 6 May 2011 10 of 32 NXP Semiconductors PCA9601 Dual bidirectional bus buffer VCC ≤ 1 mA SX (SY) Vref 002aac838 Fig 4. Equivalent circuit at SX/SY 800 VOL (mV) 700 (1) (2) 002aac839 800 VOL (mV) 700 002aac840 (1) (2) 600 600 500 500 400 −50 −25 0 25 50 75 100 125 Tj (°C) 400 −50 −25 0 25 50 75 100 125 Tj (°C) VOL at SX typical and limits over temperature. (1) Maximum. (2) Typical. VOL at SX typical and limits over temperature. (1) Maximum. (2) Typical. Fig 5. VOL as a function of junction temperature (IOL = 0.3 mA) 002aag005 Fig 6. VOL as a function of junction temperature (IOL = 3 mA) 002aag006 600 VIL (mV) 500 typical maximum 400 600 VIH (mV) 500 minimum typical 400 300 300 200 −50 −25 0 25 50 75 100 125 Tj (°C) 200 −50 −25 0 25 50 75 100 125 Tj (°C) VIL at SX changes over temperature range. VIH at SX changes over temperature range. Fig 7. VIL as a function of junction temperature; maximum and typical values Fig 8. VIH as a function of junction temperature; minimum and typical values PCA9601 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved. Product data sheet Rev. 2 — 6 May 2011 11 of 32 NXP Semiconductors PCA9601 Dual bidirectional bus buffer 1400 VCC(max) (mV) 1200 002aac075 1000 II (μA) 800 001aai062 (1) (2) 1000 600 800 400 600 200 400 −50 −25 0 25 50 75 100 125 Tj (°C) 0 −50 −25 0 25 50 75 100 125 Tj (°C) (1) Maximum. (2) Typical. Fig 9. VCC bus release limit over temperature; maximum values Fig 10. Current sourced out of SX/SY as a function of junction temperature if these pins are externally pulled to 0.4 V or lower 002aaf484 VOL (V) 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0 0 10 20 30 ISX, ISY (mA) Fig 11. Typical SX/SY current versus LOW-level output voltage PCA9601 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved. Product data sheet Rev. 2 — 6 May 2011 12 of 32 NXP Semiconductors PCA9601 Dual bidirectional bus buffer 10. Application information Refer to application notes AN10658 and AN255 for more detailed application information. VCC (2.5 V to 15 V) 5V I2C-bus SDA TX (SDA) RX (SDA) R1 'SDA' (new levels) PCA9601 002aae876 Fig 12. Interfacing a standard 3 mA I2C-bus or one with TTL levels (e.g. SMBus) to higher voltage or higher current sink (e.g. Fast-mode Plus) devices VCC VCC1 R2 R4 R5 5V I2C-bus SDA R1 RX (SDA) TX (SDA) R3 I2C-bus SDA PCA9601 002aae877 This simple example may be limited, if using lowest-cost couplers, to speeds as low as 5 kHz. Refer to application notes for schematics suitable for operation to 400 kHz or higher. Fig 13. Galvanic isolation of I2C-bus nodes via opto-couplers main enclosure 3.3 V to 5 V 12 V long cables SDA 3.3 V to 5 V 12 V remote control enclosure 12 V 3.3 V to 5 V SDA 3.3 V to 5 V SCL SCL PCA9601 PCA9601 002aae878 Fig 14. Long distance I2C-bus communication PCA9601 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved. Product data sheet Rev. 2 — 6 May 2011 13 of 32 NXP Semiconductors PCA9601 Dual bidirectional bus buffer +V cable drive VCC1 R2 R2 VCC2 VCC R2 VCC RX TX TY R1 R1 R1 R1 RX TX TY R2 SCL I2C-BUS MASTER SDA SX SX SCL I2C-BUS SLAVE(S) SY RY cable RY SY SDA PCA9601 C2 C2 PCA9601 propagation delay ≈ 5 ns/m BAT54A BAT54A C2 C2 GND GND 002aae879 Fig 15. Driving ribbon or flat telephone cables Table 7. Examples of bus capability Refer to Figure 15. VCC1 (V) +V VCC2 cable (V) (V) R1 (Ω) R2 C2 (kΩ) (pF) Cable Cable length capacitance (m) Cable delay Set master nominal SCL HIGH period (ns) 1.25 μs 600 Effective bus clock LOW period speed (kHz) (ns) 3850 125 Max. slave response delay 5 12 5 750 2.2 400 250 n/a (delay based) n/a (delay based) 1 nF 120 pF normal specification 400 kHz parts normal specification 400 kHz parts meets Fm+ specification meets Fm+ specification 5 12 5 750 2.2 220 100 500 ns 600 2450 195 3.3 3.3 5 5 3.3 3.3 330 330 1 1 220 100 25 3 125 ns 15 ns 260 260 770 720 620 690 For more examples of faster alternatives for driving over longer cables such as Cat5 communication cable, see AN10658. Communication at 1 MHz is possible over short cables and > 400 kHz is possible over 50 m of cable. PCA9601 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved. Product data sheet Rev. 2 — 6 May 2011 14 of 32 NXP Semiconductors PCA9601 Dual bidirectional bus buffer 10.1 Calculating system delays and bus clock frequency local master bus VCCM Rm buffered expansion bus VCCB Rb Rs remote slave bus VCCS MASTER SCL SCL SLAVE SX PCA9601 TX/RX TX/RX PCA9601 SX I2C-BUS Cm Cb Cs I2C-BUS master bus capacitance buffered bus wiring capacitance slave bus capacitance 002aae880 GND (0 V) Effective delay of SCL at slave: 120 + 17VCCM + (2.5 + 4 × 109 × Cb) × VCCB + 10VCCS (ns). C = F; V = V. Fig 16. Falling edge of SCL at master is delayed by the buffers and bus fall times local master bus VCCM Rm buffered expansion bus VCCB Rb MASTER SCL SX PCA9601 TX/RX TX/RX I2C-BUS Cm Cb master bus capacitance GND (0 V) buffered bus wiring capacitance 002aae881 Effective delay of SCL at master: 115 + (Rm × Cm) + (0.7 × Rb × Cb) (ns). C = F; R = Ω. Fig 17. Rising edge of SCL at master is delayed (clock stretch) by buffer and bus rise times PCA9601 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved. Product data sheet Rev. 2 — 6 May 2011 15 of 32 NXP Semiconductors PCA9601 Dual bidirectional bus buffer local master bus VCCM Rm buffered expansion bus VCCB Rb Rs remote slave bus VCCS MASTER SDA SDA SLAVE SX PCA9601 TX/RX TX/RX PCA9601 SX I2C-BUS Cm Cb Cs I2C-BUS master bus capacitance buffered bus wiring capacitance slave bus capacitance 002aae882 GND (0 V) Effective delay of SDA at master: 115 + 0.2(Rs × Cs) + 0.7[(Rb × Cb) + (Rm × Cm)] (ns). C = F; R = Ω. Fig 18. Rising edge of SDA at slave is delayed by the buffers and bus rise times Figure 16, Figure 17, and Figure 18 show the PCA9601 used to drive extended bus wiring with relatively large capacitances linking two I2C-bus nodes. It includes simplified expressions for making the relevant timing calculations for 3.3 V or 5 V operation. Because the buffers and the wiring introduce timing delays, it may be necessary to decrease the nominal SCL frequency. In most cases the actual bus frequency will be lower than the nominal Master timing due to bit-wise stretching of the clock periods. The delay factors involved in calculation of the allowed bus speed are: A — The propagation delay of the master signal through the buffers and wiring to the slave. The important delay is that of the falling edge of SCL because this edge ‘requests’ the data or acknowledge from a slave. See Figure 16. B — The effective stretching of the nominal LOW period of SCL at the master caused by the buffer and bus rise times. See Figure 17. C — The propagation delay of the slave's response signal through the buffers and wiring back to the master. The important delay is that of a rising edge in the SDA signal. Rising edges are always slower and are therefore delayed by a longer time than falling edges. (The rising edges are limited by the passive pull-up while falling edges are actively driven); see Figure 18. The timing requirement in any I2C-bus system is that a slave's data response (which is provided in response to a falling edge of SCL) must be received at the master before the end of the corresponding LOW period of SCL as appears on the bus wiring at the master. Since all slaves will, as a minimum, satisfy the worst case timing requirements of their speed class (Fast-mode, Fm+, etc.), they must provide their response, allowing for the set-up time, within the minimum allowed clock LOW period, e.g., 450 ns (max.) for Fm+ parts. In systems that introduce additional delays it may be necessary to extend the minimum clock LOW period to accommodate the ‘effective’ delay of the slave's response. The effective delay of the slave’s response equals the total delays in SCL falling edge PCA9601 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved. Product data sheet Rev. 2 — 6 May 2011 16 of 32 NXP Semiconductors PCA9601 Dual bidirectional bus buffer from the master reaching the slave (Figure 16) minus the effective delay (stretch) of the SCL rising edge (Figure 17) plus total delays in the slave's response data, carried on SDA, reaching the master (Figure 18). The master microcontroller should be programmed to produce a nominal SCL LOW period as follows: SCL L OW ≥ ( slave r esponse d elay t o v alid d ata o n i ts S DA + A – B + C + data s et - up t ime ) n s (1) The actual LOW period will become (the programmed value + the stretching time B). When this actual LOW period is then less than the specified minimum, the specified minimum should be used. Example 1: It is required to connect an Fm+ slave, with Rs × Cs product of 100 ns, to a 5 V Fast-mode system also having 100 ns Rm × Cm using two PCA9601’s to buffer a 5 V bus with 4 nF loading and 160 Ω pull-up. Calculate the allowed bus speed: Delay A = 120 + 85 + (2.5 + [4 × 4]) × 5 + 50 = 347.5 ns Delay B = 115 + 100 + 70 = 285 ns Delay C = 115 + 20 + 0.7(100 + 100) = 275 ns The maximum Fm+ slave response delay must be < 450 ns so the programmed LOW period is calculated as: LOW ≥ 450 + 347.5 − 285 + 275 + 100 = 887.5 ns The actual LOW period will be 887.5 + 285 = 1173 ns, which is below the Fast-mode minimum, so the programmed LOW period must be increased to (1300 − 285) = 1015 ns, so the actual LOW equals the 1300 ns requirement and this shows that this Fast-mode system may be safely run to its limit of 400 kHz. Example 2: It is required to buffer a Master with Fm+ speed capability, but only 3 mA sink capability, to an Fm+ bus. All the system operates at 3.3 V. The Master Rm × Cm product is 50 ns. Only one PCA9601 is used. The Fm+ bus becomes the buffered bus. The Fm+ bus has 200 pF loading and 150 Ω pull-up, so its Rb × Cb product is 30 ns. The Fm+ slave has a specified data valid time tVD;DAT maximum of 300 ns. Calculate the allowed maximum system bus speed. (Note that the fixed values in the delay equations represent the internal propagation delays of the PCA9601. Only one PCA9601 is used here, so those fixed values used below are taken from the characteristics.) The delays are: Delay A = 40 + 56 + (2.5 + [4 × 0.2]) × 3.3 = 107 ns Delay B = 115 + 50 + 21 = 186 ns Delay C = 70 + 0.7(50 + 30) = 126 ns The programmed LOW period is calculated as: SCL LOW ≥ 300 + 117 − 186 + 126 + 50 = 407 ns PCA9601 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved. Product data sheet Rev. 2 — 6 May 2011 17 of 32 NXP Semiconductors PCA9601 Dual bidirectional bus buffer The actual LOW period will be 407 + 126 = 533 ns, which exceeds the minimum Fm+ 500 ns requirement. This system requires the bus LOW period, and therefore cycle time, to be increased by 33 ns so the system must run slightly below the 1 MHz limit. The possible maximum speed has a cycle period of 1033 ns or 968 kHz. 12 V 3.3 V to 5 V TX SDA 3.3 V to 5 V TY SCL SY RY SX RX 12 V twisted-pair telephone wires, USB, or flat ribbon cables; up to 15 V logic levels, include VCC and GND 12 V 3.3 V 3.3 V PCA9601 PCA9601 SX SY PCA9601 SX SY PCA9601 SX SY PCA9601 SY SDA SX SCL 002aae883 SCL/SDA SCL/SDA SCL/SDA no limit to the number of connected bus devices Fig 19. I2C-bus multipoint application There is an Excel calculator which makes it easy to determine the maximum I2C-bus clock speed when using the PCA9601. The calculator and instructions can be found at www.nxp.com/clockspeedcalculator. PCA9601 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved. Product data sheet Rev. 2 — 6 May 2011 18 of 32 NXP Semiconductors PCA9601 Dual bidirectional bus buffer 7 VCC 6 (V) 5 4 3 2 1 0 (2) 002aac932 7 VCC 6 (V) 5 4 3 2 (2) (1) 002aac933 (1) (1) (2) 1 0 (2) (1) (2) −1 0 100 200 300 400 500 600 700 800 900 time (ns) −1 0 100 200 300 400 500 600 700 800 900 time (ns) (1) TX output. (2) SX input. (1) TX/RX output. (2) SX input. Fig 20. Propagation SX to TX with VRX = VCC = 3.3 V (SX pull-up to 3.3 V; TX pull-up to 5.7 V) Fig 21. Propagation SX to TX with RX tied to TX; VCC = 3.3 V (SX pull-up to 3.3 V; TX pull-up to 5.7 V) 002aac934 7 VCC 6 (V) 5 4 3 (2) (1) 2 (2) 1 0 −1 0 (1) 100 200 300 400 500 600 700 800 900 time (ns) (1) RX input. (2) SX output. Fig 22. Propagation RX to SX (SX pull-up to 3.3 V; VCC = 3.3 V; RX pull-up to 4.6 V) 10.2 Negative undershoot below absolute minimum value The reason why the IC pin reverse voltage on pins TX and RX in Table 5 “Limiting values” is specified at such a low value, −0.3 V, is not that applying larger voltages is likely to cause damage but that it is expected that, in normal applications, there is no reason why larger DC voltages will be applied. This ‘absolute maximum’ specification is intended to be a DC or continuous ratings and the nominal DC I2C-bus voltage LOW usually does not even reach 0 V. Inside PCA9601 at every pin there is a large protective diode connected to the GND pin and that diode will start to conduct when the pin voltage is more than about −0.55 V with respect to GND at 25 °C ambient. Figure 23 shows the measured characteristic for one of those diodes inside PCA9601. The plot was made using a curve tracer that applies 50 Hz mains voltage via a series resistor, so the pulse durations are long duration (several milliseconds) and are reaching peaks of over 2 A when more than −1.5 V is applied. The IC becomes very hot during this PCA9601 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved. Product data sheet Rev. 2 — 6 May 2011 19 of 32 NXP Semiconductors PCA9601 Dual bidirectional bus buffer testing but it was not damaged. Whenever there is current flowing in any of these diodes it is possible that there can be faulty operation of any IC. For that reason we put a specification on the negative voltage that is allowed to be applied. It is selected so that, at the highest allowed junction temperature, there will be a big safety factor that guarantees the diode will not conduct and then we do not need to make any 100 % production tests to guarantee the published specification. For the PCA9601, in specific applications, there will always be transient overshoot and ringing on the wiring that can cause these diodes to conduct. Therefore we designed the IC to withstand those transients and as a part of the qualification procedure we made tests, using DC currents to more than twice the normal bus sink currents, to be sure that the IC was not affected by those currents. For example, the TX/TY and RX/RY pins were tested to at least −80 mA which, from Figure 23, would be more than −0.8 V. The correct functioning of the PCA9601 is not affected even by those large currents. The Absolute Maximum (DC) ratings are not intended to apply to transients but to steady state conditions. This explains why you will never see any problems in practice even if, during transients, more than −0.3 V is applied to the bus interface pins of PCA9601. Figure 23 “Diode characteristic curve” also explains how the general Absolute Maximum DC specification was selected. The current at 25 °C is near zero at −0.55 V. The PCA9601 is allowed to operate with +125 °C junction and that would cause this diode voltage to decrease by 100 × 2 mV = 200 mV. So for zero current we need to specify −0.35 V and we publish −0.3 V just to have some extra margin. Remark: You should not be concerned about the transients generated on the wiring by a PCA9601 in normal applications and that is input to the TX/RX or TY/RY pins of another PCA9601. Because not all ICs that may be driven by PCA9601 are designed to tolerate negative transients, in Section 10.2.1 “Example with questions and answers” we show they can be managed if required. 0 diode current (mA) −10−1 002aaf063 −1 −10 −102 −103 −104 −2.0 −1.5 −1.0 −0.5 0 voltage (V) Fig 23. Diode characteristic curve PCA9601 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved. Product data sheet Rev. 2 — 6 May 2011 20 of 32 NXP Semiconductors PCA9601 Dual bidirectional bus buffer 10.2.1 Example with questions and answers Question: On a falling edge of TX we measure undershoot at −800 mV at the linked TX, RX pins of the PCA9601 that is generating the LOW, but the PCA9601 data sheet specifies minimum −0.3 V. Does this mean that we violate the data sheet absolute value? Answer: For PCA9601 the −0.3 V Absolute Maximum rating is not intended to apply to transients, it is a DC rating. As shown in Figure 24, there is no theoretical reason for any undershoot at the IC that is driving the bus LOW and no significant undershoot should be observed when using reasonable care with the ground connection of the ‘scope. It is more likely that undershoot observed at a driving PCA9601 is caused by local stray inductance and capacitance in the circuit and by the oscilloscope connections. As shown, undershoot will be generated by PCB traces, wiring, or cables driven by a PCA9601 because the allowed value of the I2C-bus pull-up resistor generally is larger than that required to correctly terminate the wiring. In this example, with no IC connected at the end of the wiring, the undershoot is about 2 V. 6 voltage (V) 4 send 2 receive 0 −2 horizontal scale = 62.5 ns/div time (ns) 5V 5V 300 Ω RX SX TX send 2 meter cable 5V 300 Ω receive GND 002aaf078 PCA9601 Fig 24. Transients generated by the bus wiring PCA9601 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved. Product data sheet Rev. 2 — 6 May 2011 21 of 32 NXP Semiconductors PCA9601 Dual bidirectional bus buffer Question: We have 2 meters of cable in a bus that joins the TX/RX sides of two PCA9601 devices. When one TX drives LOW the other PCA9601 TX/RX is driven to −0.8 V for over 50 ns. What is the expected value and the theoretically allowed value of undershoot? Answer: Because the cable joining the two PCA9601s is a ‘transmission line’ that will have a characteristic impedance around 100 Ω and it will be terminated by pull-up resistors that are larger than that characteristic impedance there will always be negative undershoot generated. The duration of the undershoot is a function of the cable length and the input impedance of the connected IC. As shown in Figure 25, the transient undershoot will be limited, by the diodes inside PCA9601, to around −0.8 V and that will not cause problems for PCA9601. Those transients will not be passed inside the IC to the SX/SY side of the IC. 6 voltage (V) 4 2 send 0 receive −2 horizontal scale = 62.5 ns/div time (ns) 5V 5V 300 Ω 5V 300 Ω receive 2 meter cable GND 002aaf079 5V RX SX TX send RX TX SX PCA9601 Fig 25. Wiring transients limited by the diodes in PCA9601 Question: If we input 800 mV undershoot at TX, RX pins, what kind of problem is expected? Answer: When that undershoot is generated by another PCA9601 and is simply the result of the system wiring, then there will be no problems. Question: Will we have any functional problem or reliability problem? Answer: No. PCA9601 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved. Product data sheet Rev. 2 — 6 May 2011 22 of 32 NXP Semiconductors PCA9601 Dual bidirectional bus buffer Question: If we add 100 Ω to 200 Ω at signal line, the overshoot becomes slightly smaller. Is this a good idea? Answer: No, it is not necessary to add any resistance. When the logic signal generated by TX or TY of PCA9601 drives long traces or wiring with ICs other than PCA9601 being driven, then adding a Schottky diode (BAT54A) as shown in Figure 26 will clamp the wiring undershoot to a value that will not cause conduction of the IC’s internal diodes. 6 voltage (V) 4 2 send 0 receive −2 horizontal scale = 62.5 ns/div time (ns) 5V 5V 300 Ω 5V 300 Ω receive 2 meter cable 1/2 BAT54A 5V RX SX TX send RX TX SX GND 002aaf080 PCA9601 Fig 26. Wiring transients limited by a Schottky diode PCA9601 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved. Product data sheet Rev. 2 — 6 May 2011 23 of 32 NXP Semiconductors PCA9601 Dual bidirectional bus buffer 11. Package outline SO8: plastic small outline package; 8 leads; body width 3.9 mm SOT96-1 D E A X c y HE vMA Z 8 5 Q A2 pin 1 index A1 (A 3) θ Lp L A 1 4 e bp wM detail X 0 2.5 scale 5 mm DIMENSIONS (inch dimensions are derived from the original mm dimensions) UNIT mm inches A max. 1.75 0.069 A1 0.25 0.10 A2 1.45 1.25 A3 0.25 0.01 bp 0.49 0.36 c 0.25 0.19 D (1) 5.0 4.8 0.20 0.19 E (2) 4.0 3.8 0.16 0.15 e 1.27 0.05 HE 6.2 5.8 L 1.05 Lp 1.0 0.4 Q 0.7 0.6 v 0.25 0.01 w 0.25 0.01 y 0.1 0.004 Z (1) 0.7 0.3 0.028 0.012 θ 8o o 0 0.010 0.057 0.004 0.049 0.019 0.0100 0.014 0.0075 0.244 0.039 0.028 0.041 0.228 0.016 0.024 Notes 1. Plastic or metal protrusions of 0.15 mm (0.006 inch) maximum per side are not included. 2. Plastic or metal protrusions of 0.25 mm (0.01 inch) maximum per side are not included. OUTLINE VERSION SOT96-1 REFERENCES IEC 076E03 JEDEC MS-012 JEITA EUROPEAN PROJECTION ISSUE DATE 99-12-27 03-02-18 Fig 27. Package outline SOT96-1 (SO8) PCA9601 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved. Product data sheet Rev. 2 — 6 May 2011 24 of 32 NXP Semiconductors PCA9601 Dual bidirectional bus buffer TSSOP8: plastic thin shrink small outline package; 8 leads; body width 3 mm SOT505-1 D E A X c y HE vMA Z 8 5 A2 pin 1 index A1 (A3) A θ Lp L 1 e bp 4 detail X wM 0 2.5 scale 5 mm DIMENSIONS (mm are the original dimensions) UNIT mm A max. 1.1 A1 0.15 0.05 A2 0.95 0.80 A3 0.25 bp 0.45 0.25 c 0.28 0.15 D(1) 3.1 2.9 E(2) 3.1 2.9 e 0.65 HE 5.1 4.7 L 0.94 Lp 0.7 0.4 v 0.1 w 0.1 y 0.1 Z(1) 0.70 0.35 θ 6° 0° Notes 1. Plastic or metal protrusions of 0.15 mm maximum per side are not included. 2. Plastic or metal protrusions of 0.25 mm maximum per side are not included. OUTLINE VERSION SOT505-1 REFERENCES IEC JEDEC JEITA EUROPEAN PROJECTION ISSUE DATE 99-04-09 03-02-18 Fig 28. Package outline SOT505-1 (TSSOP8) PCA9601 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved. Product data sheet Rev. 2 — 6 May 2011 25 of 32 NXP Semiconductors PCA9601 Dual bidirectional bus buffer 12. Soldering of SMD packages This text provides a very brief insight into a complex technology. A more in-depth account of soldering ICs can be found in Application Note AN10365 “Surface mount reflow soldering description”. 12.1 Introduction to soldering Soldering is one of the most common methods through which packages are attached to Printed Circuit Boards (PCBs), to form electrical circuits. The soldered joint provides both the mechanical and the electrical connection. There is no single soldering method that is ideal for all IC packages. Wave soldering is often preferred when through-hole and Surface Mount Devices (SMDs) are mixed on one printed wiring board; however, it is not suitable for fine pitch SMDs. Reflow soldering is ideal for the small pitches and high densities that come with increased miniaturization. 12.2 Wave and reflow soldering Wave soldering is a joining technology in which the joints are made by solder coming from a standing wave of liquid solder. The wave soldering process is suitable for the following: • Through-hole components • Leaded or leadless SMDs, which are glued to the surface of the printed circuit board Not all SMDs can be wave soldered. Packages with solder balls, and some leadless packages which have solder lands underneath the body, cannot be wave soldered. Also, leaded SMDs with leads having a pitch smaller than ~0.6 mm cannot be wave soldered, due to an increased probability of bridging. The reflow soldering process involves applying solder paste to a board, followed by component placement and exposure to a temperature profile. Leaded packages, packages with solder balls, and leadless packages are all reflow solderable. Key characteristics in both wave and reflow soldering are: • • • • • • Board specifications, including the board finish, solder masks and vias Package footprints, including solder thieves and orientation The moisture sensitivity level of the packages Package placement Inspection and repair Lead-free soldering versus SnPb soldering 12.3 Wave soldering Key characteristics in wave soldering are: • Process issues, such as application of adhesive and flux, clinching of leads, board transport, the solder wave parameters, and the time during which components are exposed to the wave • Solder bath specifications, including temperature and impurities PCA9601 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved. Product data sheet Rev. 2 — 6 May 2011 26 of 32 NXP Semiconductors PCA9601 Dual bidirectional bus buffer 12.4 Reflow soldering Key characteristics in reflow soldering are: • Lead-free versus SnPb soldering; note that a lead-free reflow process usually leads to higher minimum peak temperatures (see Figure 29) than a SnPb process, thus reducing the process window • Solder paste printing issues including smearing, release, and adjusting the process window for a mix of large and small components on one board • Reflow temperature profile; this profile includes preheat, reflow (in which the board is heated to the peak temperature) and cooling down. It is imperative that the peak temperature is high enough for the solder to make reliable solder joints (a solder paste characteristic). In addition, the peak temperature must be low enough that the packages and/or boards are not damaged. The peak temperature of the package depends on package thickness and volume and is classified in accordance with Table 8 and 9 Table 8. SnPb eutectic process (from J-STD-020C) Package reflow temperature (°C) Volume (mm3) < 350 < 2.5 ≥ 2.5 Table 9. 235 220 Lead-free process (from J-STD-020C) Package reflow temperature (°C) Volume (mm3) < 350 < 1.6 1.6 to 2.5 > 2.5 260 260 250 350 to 2000 260 250 245 > 2000 260 245 245 ≥ 350 220 220 Package thickness (mm) Package thickness (mm) Moisture sensitivity precautions, as indicated on the packing, must be respected at all times. Studies have shown that small packages reach higher temperatures during reflow soldering, see Figure 29. PCA9601 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved. Product data sheet Rev. 2 — 6 May 2011 27 of 32 NXP Semiconductors PCA9601 Dual bidirectional bus buffer temperature maximum peak temperature = MSL limit, damage level minimum peak temperature = minimum soldering temperature peak temperature time 001aac844 MSL: Moisture Sensitivity Level Fig 29. Temperature profiles for large and small components For further information on temperature profiles, refer to Application Note AN10365 “Surface mount reflow soldering description”. 13. Abbreviations Table 10. Acronym CDM ESD HBM I2C-bus I/O IC MM PMBus SCL SDA SMBus TTL Abbreviations Description Charged-Device Model ElectroStatic Discharge Human Body Model Inter-Integrated Circuit bus Input/Output Integrated Circuit Machine Model Power Management Bus Serial Clock Line Serial DAta line System Management Bus Transistor-Transistor Logic PCA9601 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved. Product data sheet Rev. 2 — 6 May 2011 28 of 32 NXP Semiconductors PCA9601 Dual bidirectional bus buffer 14. Revision history Table 11. Revision history Release date 20110506 Data sheet status Product data sheet Change notice Supersedes PCA9601 v.1 Document ID PCA9601 v.2 Modifications: • • • Section 2 “Features and benefits”, eighth bullet item: deleted phrase “450 V MM per JESD22-A115”. Table 6 “Characteristics”, sub-section “Bus pull-up (load) voltages and current, Pins SX and SY; I2C-bus”: changed IO Max value from “2 mA” to “15 mA”. Table 6 “Characteristics”, sub-section “Input logic switching threshold voltages, Pins SX and SY”: – Changed VIL Min value from “425 mV” to “-”. – Changed VIL Typ value from “500 mV” to “-”. – Changed VIL Max value from “-” to “425 mV”. – Changed Vth(IH) Min value from “-” to “580 mV”. – Changed Vth(IH) Typ value from “500 mV” to “-”. – Changed Vth(IH) Max value from “580 mV” to “-”. • • • • PCA9601 v.1 Table 6 “Characteristics”, sub-section “Input logic switching threshold voltages, Pins TX and TY”: – Under Conditions for IO, output current: deleted word “dynamic”. Table 6 “Characteristics”: Table note [1] re-written. Figure 7 modified to add “typical” curve. Figure 8 modified to add “typical” curve. Product data sheet - 20100528 PCA9601 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved. Product data sheet Rev. 2 — 6 May 2011 29 of 32 NXP Semiconductors PCA9601 Dual bidirectional bus buffer 15. Legal information 15.1 Data sheet status Document status[1][2] Objective [short] data sheet Preliminary [short] data sheet Product [short] data sheet [1] [2] [3] Product status[3] Development Qualification Production Definition This document contains data from the objective specification for product development. This document contains data from the preliminary specification. This document contains the product specification. Please consult the most recently issued document before initiating or completing a design. The term ‘short data sheet’ is explained in section “Definitions”. The product status of device(s) described in this document may have changed since this document was published and may differ in case of multiple devices. The latest product status information is available on the Internet at URL http://www.nxp.com. 15.2 Definitions Draft — The document is a draft version only. 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NXP Semiconductors does not accept any liability related to any default, damage, costs or problem which is based on any weakness or default in the customer’s applications or products, or the application or use by customer’s third party customer(s). Customer is responsible for doing all necessary testing for the customer’s applications and products using NXP Semiconductors products in order to avoid a default of the applications and the products or of the application or use by customer’s third party customer(s). NXP does not accept any liability in this respect. Limiting values — Stress above one or more limiting values (as defined in the Absolute Maximum Ratings System of IEC 60134) will cause permanent damage to the device. Limiting values are stress ratings only and (proper) operation of the device at these or any other conditions above those given in the Recommended operating conditions section (if present) or the Characteristics sections of this document is not warranted. Constant or repeated exposure to limiting values will permanently and irreversibly affect the quality and reliability of the device. Terms and conditions of commercial sale — NXP Semiconductors products are sold subject to the general terms and conditions of commercial sale, as published at http://www.nxp.com/profile/terms, unless otherwise agreed in a valid written individual agreement. In case an individual agreement is concluded only the terms and conditions of the respective agreement shall apply. NXP Semiconductors hereby expressly objects to applying the customer’s general terms and conditions with regard to the purchase of NXP Semiconductors products by customer. No offer to sell or license — Nothing in this document may be interpreted or construed as an offer to sell products that is open for acceptance or the grant, conveyance or implication of any license under any copyrights, patents or other industrial or intellectual property rights. Export control — This document as well as the item(s) described herein may be subject to export control regulations. Export might require a prior authorization from national authorities. © NXP B.V. 2011. All rights reserved. 15.3 Disclaimers Limited warranty and liability — Information in this document is believed to be accurate and reliable. However, NXP Semiconductors does not give any representations or warranties, expressed or implied, as to the accuracy or completeness of such information and shall have no liability for the consequences of use of such information. In no event shall NXP Semiconductors be liable for any indirect, incidental, punitive, special or consequential damages (including - without limitation - lost profits, lost savings, business interruption, costs related to the removal or replacement of any products or rework charges) whether or not such damages are based on tort (including negligence), warranty, breach of contract or any other legal theory. Notwithstanding any damages that customer might incur for any reason whatsoever, NXP Semiconductors’ aggregate and cumulative liability towards customer for the products described herein shall be limited in accordance with the Terms and conditions of commercial sale of NXP Semiconductors. Right to make changes — NXP Semiconductors reserves the right to make changes to information published in this document, including without limitation specifications and product descriptions, at any time and without notice. This document supersedes and replaces all information supplied prior to the publication hereof. Suitability for use — NXP Semiconductors products are not designed, authorized or warranted to be suitable for use in life support, life-critical or safety-critical systems or equipment, nor in applications where failure or PCA9601 All information provided in this document is subject to legal disclaimers. Product data sheet Rev. 2 — 6 May 2011 30 of 32 NXP Semiconductors PCA9601 Dual bidirectional bus buffer own risk, and (c) customer fully indemnifies NXP Semiconductors for any liability, damages or failed product claims resulting from customer design and use of the product for automotive applications beyond NXP Semiconductors’ standard warranty and NXP Semiconductors’ product specifications. Non-automotive qualified products — Unless this data sheet expressly states that this specific NXP Semiconductors product is automotive qualified, the product is not suitable for automotive use. It is neither qualified nor tested in accordance with automotive testing or application requirements. NXP Semiconductors accepts no liability for inclusion and/or use of non-automotive qualified products in automotive equipment or applications. In the event that customer uses the product for design-in and use in automotive applications to automotive specifications and standards, customer (a) shall use the product without NXP Semiconductors’ warranty of the product for such automotive applications, use and specifications, and (b) whenever customer uses the product for automotive applications beyond NXP Semiconductors’ specifications such use shall be solely at customer’s 15.4 Trademarks Notice: All referenced brands, product names, service names and trademarks are the property of their respective owners. I2C-bus — logo is a trademark of NXP B.V. 16. Contact information For more information, please visit: http://www.nxp.com For sales office addresses, please send an email to: salesaddresses@nxp.com PCA9601 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved. Product data sheet Rev. 2 — 6 May 2011 31 of 32 NXP Semiconductors PCA9601 Dual bidirectional bus buffer 17. Contents 1 2 3 4 4.1 5 6 6.1 6.2 7 7.1 7.1.1 7.1.2 7.2 7.3 7.4 General description . . . . . . . . . . . . . . . . . . . . . . 1 Features and benefits . . . . . . . . . . . . . . . . . . . . 1 Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Ordering information . . . . . . . . . . . . . . . . . . . . . 2 Ordering options . . . . . . . . . . . . . . . . . . . . . . . . 2 Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Pinning information . . . . . . . . . . . . . . . . . . . . . . 3 Pinning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Pin description . . . . . . . . . . . . . . . . . . . . . . . . . 3 Functional description . . . . . . . . . . . . . . . . . . . 4 Static level offset card side . . . . . . . . . . . . . . . . 4 Fast-mode operation . . . . . . . . . . . . . . . . . . . . 4 Fast-mode Plus operation . . . . . . . . . . . . . . . . 4 High drive, long distance side. . . . . . . . . . . . . . 5 Connections to other bus buffers . . . . . . . . . . . 5 Comparison of PCA9601/PCA9600 and P82B96 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 8 Limiting values. . . . . . . . . . . . . . . . . . . . . . . . . . 7 9 Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . 8 10 Application information. . . . . . . . . . . . . . . . . . 13 10.1 Calculating system delays and bus clock frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 10.2 Negative undershoot below absolute minimum value . . . . . . . . . . . . . . . . . . . . . . . . 19 10.2.1 Example with questions and answers. . . . . . . 21 11 Package outline . . . . . . . . . . . . . . . . . . . . . . . . 24 12 Soldering of SMD packages . . . . . . . . . . . . . . 26 12.1 Introduction to soldering . . . . . . . . . . . . . . . . . 26 12.2 Wave and reflow soldering . . . . . . . . . . . . . . . 26 12.3 Wave soldering . . . . . . . . . . . . . . . . . . . . . . . . 26 12.4 Reflow soldering . . . . . . . . . . . . . . . . . . . . . . . 27 13 Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . . 28 14 Revision history . . . . . . . . . . . . . . . . . . . . . . . . 29 15 Legal information. . . . . . . . . . . . . . . . . . . . . . . 30 15.1 Data sheet status . . . . . . . . . . . . . . . . . . . . . . 30 15.2 Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 15.3 Disclaimers . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 15.4 Trademarks. . . . . . . . . . . . . . . . . . . . . . . . . . . 31 16 Contact information. . . . . . . . . . . . . . . . . . . . . 31 17 Contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 Please be aware that important notices concerning this document and the product(s) described herein, have been included in section ‘Legal information’. © NXP B.V. 2011. All rights reserved. For more information, please visit: http://www.nxp.com For sales office addresses, please send an email to: salesaddresses@nxp.com Date of release: 6 May 2011 Document identifier: PCA9601