PCA9551 8-bit I2C-bus LED driver with programmable blink rates Rev. 08 — 31 July 2008 Product data sheet 1. General description The PCA9551 LED blinker blinks LEDs in I2C-bus and SMBus applications where it is necessary to limit bus traffic or free up the I2C-bus master's (MCU, MPU, DSP, chip set, etc.) timer. The uniqueness of this device is the internal oscillator with two programmable blink rates. To blink LEDs using normal I/O expanders like the PCF8574 or PCA9554, the bus master must send repeated commands to turn the LED on and off. This greatly increases the amount of traffic on the I2C-bus and uses up one of the master's timers. The PCA9551 LED blinker instead requires only the initial set-up command to program BLINK RATE 1 and BLINK RATE 2 (i.e., the frequency and duty cycle) for each individual output. From then on, only one command from the bus master is required to turn each individual open-drain output on, off, or to cycle at BLINK RATE 1 or BLINK RATE 2. Maximum output sink current is 25 mA per bit and 100 mA per package. Any bits not used for controlling the LEDs can be used for General Purpose parallel Input/Output (GPIO) expansion. The active LOW hardware reset pin (RESET) and Power-On Reset (POR) initializes the registers to their default state, all zeroes, causing the bits to be set HIGH (LED off). Three hardware address pins on the PCA9551 allow eight devices to operate on the same bus. The newer Fast-mode Plus PCA9634 8-bit LED controller offers an individual PWM dimming control for each channel for better color mixing capabilities with a global PWM for dimming or blinking all channels at the same time. There are 126 possible address combinations and the maximum output sink current is 25 mA per bit and 200 mA per package. 2. Features n 8 LED drivers (on, off, flashing at a programmable rate) n 2 selectable, fully programmable blink rates (frequency and duty cycle) between 0.148 Hz and 38 Hz (6.74 seconds and 0.026 seconds) n Input/outputs not used as LED drivers can be used as regular GPIOs n Internal oscillator requires no external components n I2C-bus interface logic compatible with SMBus n Internal power-on reset n Noise filter on SCL/SDA inputs n Active LOW reset input n 8 open-drain outputs directly drive LEDs to 25 mA n Edge rate control on outputs PCA9551 NXP Semiconductors 8-bit I2C-bus LED driver with programmable blink rates n n n n n n No glitch on power-up Supports hot insertion Low standby current Operating power supply voltage range of 2.3 V to 5.5 V 0 Hz to 400 kHz clock frequency ESD protection exceeds 2000 V HBM per JESD22-A114, 150 V MM per JESD22-A115 and 1000 V CDM per JESD22-C101 n Latch-up testing is done to JEDEC Standard JESD78 which exceeds 100 mA n Packages offered: SO16, TSSOP16, HVQFN16 3. Ordering information Table 1. Ordering information Tamb = −40 °C to +85 °C. Type number Topside mark Package Name Description Version PCA9551D PCA9551D SO16 plastic small outline package; 16 leads; body width 3.9 mm SOT109-1 PCA9551PW PCA9551 TSSOP16 plastic thin shrink small outline package; 16 leads; body width 4.4 mm SOT403-1 PCA9551BS 9551 HVQFN16 plastic thermal enhanced very thin quad flat package; no leads; 16 terminals; body 4 × 4 × 0.85 mm SOT629-1 4. Block diagram A0 A1 A2 PCA9551 SCL SDA INPUT REGISTER INPUT FILTERS I2C-BUS CONTROL LED SELECT (LSn) REGISTER 0 VDD RESET 1 POWER-ON RESET OSCILLATOR PRESCALER 0 REGISTER PWM0 REGISTER BLINK0 PRESCALER 1 REGISTER PWM1 REGISTER BLINK1 LEDn VSS 002aac504 Only one I/O shown for clarity. Fig 1. Block diagram of PCA9551 PCA9551_8 Product data sheet © NXP B.V. 2008. All rights reserved. Rev. 08 — 31 July 2008 2 of 26 PCA9551 NXP Semiconductors 8-bit I2C-bus LED driver with programmable blink rates 5. Pinning information 5.1 Pinning A0 1 A1 2 16 VDD 15 SDA A0 1 A1 2 16 VDD 15 SDA 14 SCL A2 3 14 SCL A2 3 LED0 4 13 RESET LED0 4 LED1 5 12 LED7 LED1 5 LED2 6 11 LED6 LED2 6 11 LED6 LED3 7 10 LED5 LED3 7 10 LED5 VSS 8 9 VSS 8 PCA9551D LED4 PCA9551PW 12 LED7 9 002aac500 LED4 002aac501 A2 16 A1 terminal 1 index area Pin configuration for TSSOP16 13 SDA Fig 3. 14 VDD Pin configuration for SO16 15 A0 Fig 2. 13 RESET 1 12 SCL LED0 2 LED1 3 10 LED7 11 RESET LED2 4 9 5 6 7 8 LED3 VSS LED4 LED5 PCA9551BS LED6 002aac502 Transparent top view Fig 4. Pin configuration for HVQFN16 5.2 Pin description Table 2. Pin description Symbol Pin Description SO16, TSSOP16 HVQFN16 A0 1 15 A1 2 16 address input 1 A2 3 1 address input 2 LED0 4 2 LED driver 0 LED1 5 3 LED driver 1 LED2 6 4 LED driver 2 LED3 7 5 LED driver 3 VSS 8 6[1] supply ground LED4 9 7 LED driver 4 LED5 10 8 LED driver 5 LED6 11 9 LED driver 6 address input 0 PCA9551_8 Product data sheet © NXP B.V. 2008. All rights reserved. Rev. 08 — 31 July 2008 3 of 26 PCA9551 NXP Semiconductors 8-bit I2C-bus LED driver with programmable blink rates Table 2. Pin description …continued Symbol Pin Description SO16, TSSOP16 HVQFN16 LED7 12 10 LED driver 7 RESET 13 11 reset input (active LOW) SCL 14 12 serial clock line SDA 15 13 serial data line VDD 16 14 supply voltage [1] HVQFN16 package die supply ground is connected to both VSS pin and exposed center pad. VSS pin must be connected to supply ground for proper device operation. For enhanced thermal, electrical, and board level performance, the exposed pad needs to be soldered to the board using a corresponding thermal pad on the board and for proper heat conduction through the board, thermal vias need to be incorporated in the PCB in the thermal pad region. 6. Functional description Refer to Figure 1 “Block diagram of PCA9551”. 6.1 Device address Following a START condition, the bus master must output the address of the slave it is accessing. The address of the PCA9551 is shown in Figure 5. To conserve power, no internal pull-up resistors are incorporated on the hardware selectable address pins and they must be pulled HIGH or LOW. slave address 1 1 0 0 fixed A2 A1 A0 R/W hardware selectable 002aac505 Fig 5. PCA9551 slave address The last bit of the address byte defines the operation to be performed. When set to logic 1 a read is selected, while a logic 0 selects a write operation. 6.2 Control register Following the successful acknowledgement of the slave address, the bus master will send a byte to the PCA9551, which will be stored in the Control register. 0 0 0 AI Auto-Increment flag 0 B2 B1 B0 register address 002aac506 Reset state: 00h Fig 6. Control register The lowest 3 bits are used as a pointer to determine which register will be accessed. PCA9551_8 Product data sheet © NXP B.V. 2008. All rights reserved. Rev. 08 — 31 July 2008 4 of 26 PCA9551 NXP Semiconductors 8-bit I2C-bus LED driver with programmable blink rates If the Auto-Increment (AI) flag is set, the three low order bits of the Control register are automatically incremented after a read or write. This allows the user to program the registers sequentially. The contents of these bits will rollover to ‘000’ after the last register is accessed. When the Auto-Increment flag is set (AI = 1) and a read sequence is initiated, the sequence must start by reading a register different from ‘0' (B2 B1 B0 ≠ 000). Only the 3 least significant bits are affected by the AI flag. Unused bits must be programmed with zeroes. 6.2.1 Control register definition Table 3. Register summary B2 B1 B0 Symbol Access Description 0 0 0 INPUT read only input register 0 0 1 PSC0 read/write frequency prescaler 0 0 1 0 PWM0 read/write PWM register 0 0 1 1 PSC1 read/write frequency prescaler 1 1 0 0 PWM1 read/write PWM register 1 1 0 1 LS0 read/write LED0 to LED3 selector 1 1 0 LS1 read/write LED4 to LED7 selector 6.3 Register descriptions 6.3.1 INPUT - Input register The INPUT register reflects the state of the device pins. Writes to this register will be acknowledged but will have no effect. Table 4. Bit INPUT - Input register description 7 6 5 4 3 2 1 0 Symbol LED7 LED6 LED5 LED4 LED3 LED2 LED1 LED0 Default X X X X X X X X Remark: The default value ‘X’ is determined by the externally applied logic level (normally logic 1) when used for directly driving LED with pull-up to VDD. 6.3.2 PSC0 - Frequency Prescaler 0 PSC0 is used to program the period of the PWM output. The period of BLINK0 = (PSC0 + 1) / 38. Remark: Prescaler calculation is different between the PCA9551 and other PCA955x LED blinkers. A divider ratio of 38 instead of 44 is used. This different divider ratio causes the blinking frequency to be 13 % (1 − 38 / 44) lower when the same 8-bit word is used. The programmed value of Frequency Prescaler 0 must be adjusted to compensate for this difference in applications where the PCA9551 is used in conjunction with other PCA955x LED blinkers and the observed blinking frequencies need to be the same. PCA9551_8 Product data sheet © NXP B.V. 2008. All rights reserved. Rev. 08 — 31 July 2008 5 of 26 PCA9551 NXP Semiconductors 8-bit I2C-bus LED driver with programmable blink rates Table 5. Bit PSC0 - Frequency Prescaler 0 register description 7 6 5 4 3 2 1 0 Symbol PSC0[7] PSC0[6] PSC0[5] PSC0[4] PSC0[3] PSC0[2] PSC0[1] PSC0[0] Default 1 1 1 1 1 1 1 1 6.3.3 PWM0 - Pulse Width Modulation 0 The PWM0 register determines the duty cycle of BLINK0. The outputs are LOW (LED off) when the count is less than the value in PWM0 and HIGH when it is greater. If PWM0 is programmed with 00h, then the PWM0 output is always LOW. The duty cycle of BLINK0 = (256 − PWM0) / 256. Table 6. Bit PWM0 - Pulse Width Modulation 0 register description 7 6 5 4 3 2 1 0 Symbol PWM0 [7] PWM0 [6] PWM0 [5] PWM0 [4] PWM0 [3] PWM0 [2] PWM0 [1] PWM0 [0] Default 1 0 0 0 0 0 0 0 6.3.4 PSC1 - Frequency Prescaler 1 PSC1 is used to program the period of the PWM output. The period of BLINK1 = (PSC1 + 1) / 38. Remark: Prescaler calculation is different between the PCA9551 and other PCA955x LED blinkers. A divider ratio of 38 instead of 44 is used. This different divider ratio causes the blinking frequency to be 13 % (1 − 38 / 44) lower when the same 8-bit word is used. The programmed value of Frequency Prescaler 1 must be adjusted to compensate for this difference in applications where the PCA9551 is used in conjunction with other PCA955x LED blinkers and the observed blinking frequencies need to be the same. Table 7. Bit PSC1 - Frequency Prescaler 1 register description 7 6 5 4 3 2 1 0 Symbol PSC1[7] PSC1[6] PSC1[5] PSC1[4] PSC1[3] PSC1[2] PSC1[1] PSC1[0] Default 1 1 1 1 1 1 1 1 6.3.5 PWM1 - Pulse Width Modulation 1 The PWM1 register determines the duty cycle of BLINK1. The outputs are LOW (LED off) when the count is less than the value in PWM1 and HIGH when it is greater. If PWM1 is programmed with 00h, then the PWM1 output is always LOW (LED off). The duty cycle of BLINK1 = (256 − PWM1) / 256. Table 8. Bit PWM1 - Pulse Width Modulation 1 register description 7 6 5 4 3 2 1 0 Symbol PWM1 [7] PWM1 [6] PWM1 [5] PWM1 [4] PWM1 [3] PWM1 [2] PWM1 [1] PWM1 [0] Default 1 0 0 0 0 0 0 0 PCA9551_8 Product data sheet © NXP B.V. 2008. All rights reserved. Rev. 08 — 31 July 2008 6 of 26 PCA9551 NXP Semiconductors 8-bit I2C-bus LED driver with programmable blink rates 6.3.6 LS0 to LS1 - LED selector registers The LSn LED select registers determine the source of the LED data. 00 = output is set LOW (LED on) 01 = output is set high-impedance (LED off; default) 10 = output blinks at PWM0 rate 11 = output blinks at PWM1 rate Table 9. LS0 to LS1 - LED selector registers bit description Legend: * default value. Register Bit Value Description LS0 - LED0 to LED3 selector LS0 7:6 01* LED3 selected 5:4 01* LED2 selected 3:2 01* LED1 selected 1:0 01* LED0 selected LS1 - LED4 to LED7 selector LS1 7:6 01* LED7 selected 5:4 01* LED6 selected 3:2 01* LED5 selected 1:0 01* LED4 selected 6.4 Pins used as GPIOs LED pins not used to control LEDs can be used as general purpose I/Os (GPIOs). For use as input, set LEDn to high-impedance (01) and then read the pin state via the Input register. For use as output, connect external pull-up resistor to the pin and size it according to the DC recommended operating characteristics. LEDn output pin is HIGH when the output is programmed as high-impedance, and LOW when the output is programmed LOW through the ‘LED selector’ register. The output can be pulse-width controlled when PWM0 or PWM1 are used. 6.5 Power-on reset When power is applied to VDD, an internal Power-On Reset (POR) holds the PCA9551 in a reset condition until VDD has reached VPOR. At that point, the reset condition is released and the PCA9551 registers are initialized to their default states, all the outputs in the OFF state. Thereafter, VDD must be lowered below 0.2 V to reset the device. 6.6 External RESET A reset can be accomplished by holding the RESET pin LOW for a minimum of tw(rst). The PCA9551 registers and I2C-bus state machine will be held in their default states until the RESET input is once again HIGH. This input requires a pull-up resistor to VDD if no active connection is used. PCA9551_8 Product data sheet © NXP B.V. 2008. All rights reserved. Rev. 08 — 31 July 2008 7 of 26 PCA9551 NXP Semiconductors 8-bit I2C-bus LED driver with programmable blink rates 7. Characteristics of the I2C-bus 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. 7.1 Bit transfer 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 7). SDA SCL data line stable; data valid Fig 7. change of data allowed mba607 Bit transfer 7.1.1 START and STOP conditions 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 8). SDA SDA SCL SCL S P START condition STOP condition mba608 Fig 8. Definition of START and STOP conditions 7.2 System configuration 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 9). PCA9551_8 Product data sheet © NXP B.V. 2008. All rights reserved. Rev. 08 — 31 July 2008 8 of 26 PCA9551 NXP Semiconductors 8-bit I2C-bus LED driver with programmable blink rates SDA SCL MASTER TRANSMITTER/ RECEIVER SLAVE RECEIVER SLAVE TRANSMITTER/ RECEIVER MASTER TRANSMITTER MASTER TRANSMITTER/ RECEIVER I2C-BUS MULTIPLEXER SLAVE 002aaa966 Fig 9. System configuration 7.3 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 S START condition 2 8 9 clock pulse for acknowledgement 002aaa987 Fig 10. Acknowledgement on the I2C-bus PCA9551_8 Product data sheet © NXP B.V. 2008. All rights reserved. Rev. 08 — 31 July 2008 9 of 26 PCA9551 NXP Semiconductors 8-bit I2C-bus LED driver with programmable blink rates 7.4 Bus transactions SCL 1 2 3 4 5 6 7 8 9 slave address 1 SDA S 1 0 data to register command byte 0 A2 A1 A0 0 START condition A R/W 0 0 0 AI 0 B2 B1 B0 A DATA 1 A acknowledge from slave acknowledge from slave acknowledge from slave write to register tv(Q) data out from port DATA 1 VALID 002aac507 Fig 11. Write to register slave address SDA S 1 1 0 command byte 0 A2 A1 A0 0 START condition 0 A 0 1 1 0 AI 0 A2 A1 A0 1 (repeated) START condition (cont.) 0 B2 B1 B0 A acknowledge from slave R/W acknowledge from slave slave address (cont.) S 0 data from register DATA (first byte) A data from register Auto-Increment register address if AI = 1 R/W acknowledge from slave DATA (last byte) A acknowledge from master NA P STOP condition no acknowledge from master at this moment master-transmitter becomes master-receiver and slave-receiver becomes slave-transmitter 002aac508 Fig 12. Read from register no acknowledge from master slave address SDA S 1 1 0 0 A2 A1 A0 1 START condition data from port data from port R/W A A DATA 1 DATA 4 acknowledge from master acknowledge from slave NA P STOP condition read from port th(D) data into port tsu(D) DATA 2 DATA 3 DATA 4 002aac509 Remark: This figure assumes the command byte has previously been programmed with 00h. Fig 13. Read Input Port register PCA9551_8 Product data sheet © NXP B.V. 2008. All rights reserved. Rev. 08 — 31 July 2008 10 of 26 PCA9551 NXP Semiconductors 8-bit I2C-bus LED driver with programmable blink rates 8. Application design-in information 5V 5V 10 kΩ 10 kΩ 10 kΩ VDD I2C-BUS/SMBus PCA9551 MASTER SDA SDA LED0 SCL SCL LED1 LED2 LED3 RESET LED4 LED5 LED6 GPIOs LED7 A2 A1 A0 VSS 002aac510 LED0 to LED5 are used as LED drivers. LED6 and LED7 are used as regular GPIOs. Fig 14. Typical application 8.1 Minimizing IDD when the I/Os are used to control LEDs When the I/Os are used to control LEDs, they are normally connected to VDD through a resistor as shown in Figure 14. Since the LED acts as a diode, when the LED is off the I/O VI is about 1.2 V less than VDD. The supply current, IDD, increases as VI becomes lower than VDD and is specified as ∆IDD in Table 12 “Static characteristics”. Designs needing to minimize current consumption, such as battery power applications, should consider maintaining the I/O pins greater than or equal to VDD when the LED is off. Figure 15 shows a high value resistor in parallel with the LED. Figure 16 shows VDD less than the LED supply voltage by at least 1.2 V. Both of these methods maintain the I/O VI at or above VDD and prevents additional supply current consumption when the LED is off. VDD VDD LED 100 kΩ LEDn VDD 5V LED LEDn 002aac189 Fig 15. High value resistor in parallel with the LED PCA9551_8 Product data sheet 3.3 V 002aac190 Fig 16. Device supplied by a lower voltage © NXP B.V. 2008. All rights reserved. Rev. 08 — 31 July 2008 11 of 26 PCA9551 NXP Semiconductors 8-bit I2C-bus LED driver with programmable blink rates 8.2 Programming example The following example will show how to set LED0 to LED3 on. It will then set LED4 and LED5 to blink at 1 Hz at a 50 % duty cycle. LED6 and LED7 will be set to blink at 4 Hz and at a 25 % duty cycle. Table 10. Programming PCA9551 Program sequence I2C-bus START S PCA9551 address with A0 to A2 = LOW C0h PSC0 subaddress + Auto-Increment 11h Set prescaler PSC0 to achieve a period of 1 second: 25h PSC0 + 1 Blink period = 1 = -----------------------38 PSC0 = 37 Set PWM0 duty cycle to 50 %: 80h 256 – PWM0 -------------------------------- = 0.5 256 PWM0 = 128 Set prescaler PSC1 to achieve a period of 0.25 seconds: 09h PSC1 + 1 Blink period = 0.25 = -----------------------38 PSC1 = 9 Set PWM1 output duty cycle to 25 %: C0h 256 – PWM1 -------------------------------- = 0.25 256 PWM1 = 192 Set LED0 to LED3 on 00h Set LED4 and LED5 to PWM0, and LED6 or LED7 to PWM1 FAh STOP P 9. Limiting values Table 11. Limiting values In accordance with the Absolute Maximum Rating System (IEC 60134). Symbol Parameter VDD Conditions Min Max Unit supply voltage −0.5 +6.0 V VI/O voltage on an input/output pin VSS − 0.5 5.5 V IO(LEDn) output current on pin LEDn - ±25 mA ISS ground supply current - 100 mA Ptot total power dissipation - 400 mW Tstg storage temperature −65 +150 °C Tamb ambient temperature −40 +85 °C operating PCA9551_8 Product data sheet © NXP B.V. 2008. All rights reserved. Rev. 08 — 31 July 2008 12 of 26 PCA9551 NXP Semiconductors 8-bit I2C-bus LED driver with programmable blink rates 10. Static characteristics Table 12. Static characteristics VDD = 2.3 V to 5.5 V; VSS = 0 V; Tamb = −40 °C to +85 °C; unless otherwise specified. Symbol Parameter Conditions Min Typ[1] Max Unit Supplies VDD supply voltage 2.3 - 5.5 V IDD supply current operating mode; VDD = 5.5 V; VI = VDD or VSS; fSCL = 100 kHz - 350 500 µA Istb standby current Standby mode; VDD = 5.5 V; VI = VDD or VSS; fSCL = 0 kHz - 1.9 3.0 µA ∆IDD additional quiescent supply Standby mode; VDD = 5.5 V; current every LED I/O at VI = 4.3 V; fSCL = 0 kHz - - 800 µA VPOR power-on reset voltage - 1.7 2.2 V no load; VI = VDD or VSS [2] Input SCL; input/output SDA VIL LOW-level input voltage −0.5 - +0.3VDD V VIH HIGH-level input voltage 0.7VDD - 5.5 V IOL LOW-level output current VOL = 0.4 V 3 6.5 - mA IL leakage current VI = VDD = VSS −1 - +1 µA Ci input capacitance VI = VSS - 3.7 5 pF I/Os VIL LOW-level input voltage −0.5 - +0.8 V VIH HIGH-level input voltage 2.0 - 5.5 V IOL LOW-level output current VOL = 0.4 V VDD = 2.3 V [3] 6 9 - mA VDD = 3.0 V [3] 8 11 - mA VDD = 5.0 V [3] 10 14 - mA VDD = 2.3 V [3] 11 14 - mA VDD = 3.0 V [3] 14 18 - mA VDD = 5.0 V [3] 17 24 - mA −1 - +1 µA - 2.1 5 pF −0.5 - +0.8 V A0; RESET 2.0 - 5.5 V A1; A2 2.0 - VDD + 0.5 V VOL = 0.7 V ILI input leakage current Cio input/output capacitance VDD = 3.6 V; VI = 0 V or VDD Select inputs A0, A1, A2; RESET VIL LOW-level input voltage VIH HIGH-level input voltage ILI input leakage current −1 - +1 µA Ci input capacitance - 2.3 5 pF [1] Typical limits at VDD = 3.3 V, Tamb = 25 °C. [2] VDD must be lowered to 0.2 V in order to reset part. [3] Each I/O must be externally limited to a maximum of 25 mA and the device must be limited to a maximum current of 100 mA. PCA9551_8 Product data sheet © NXP B.V. 2008. All rights reserved. Rev. 08 — 31 July 2008 13 of 26 PCA9551 NXP Semiconductors 8-bit I2C-bus LED driver with programmable blink rates 20 % 002aac191 20 % (1) percent variation 002aac192 (1) percent variation 0% 0% (2) −20 % (3) (2) −20 % (3) −40 % −40 −20 0 20 40 60 100 Tamb (°C) 80 −40 % −40 −20 (1) maximum (1) maximum (2) average (2) average (3) minimum (3) minimum Fig 17. Typical frequency variation over process at VDD = 2.3 V to 3.0 V 20 40 60 100 80 Tamb (°C) Fig 18. Typical frequency variation over process at VDD = 3.0 V to 5.5 V PCA9551_8 Product data sheet 0 © NXP B.V. 2008. All rights reserved. Rev. 08 — 31 July 2008 14 of 26 PCA9551 NXP Semiconductors 8-bit I2C-bus LED driver with programmable blink rates 11. Dynamic characteristics Table 13. Dynamic characteristics Symbol Parameter Conditions Standard-mode I2C-bus Min Max Fast-mode I2C-bus Min Max Unit fSCL SCL clock frequency 0 100 0 400 tBUF bus free time between a STOP and START condition 4.7 - 1.3 - µs tHD;STA hold time (repeated) START condition 4.0 - 0.6 - µs tSU;STA set-up time for a repeated START condition 4.7 - 0.6 - µs tSU;STO set-up time for STOP condition 4.0 - 0.6 - µs tHD;DAT data hold time tVD;ACK data valid acknowledge time tVD;DAT data valid time kHz 0 - 0 - ns [1] - 600 - 600 ns LOW-level [2] - 600 - 600 ns HIGH-level [2] - 1500 - 600 ns tSU;DAT data set-up time 250 - 100 - ns tLOW LOW period of the SCL clock 4.7 - 1.3 - µs tHIGH HIGH period of the SCL clock 4.0 - 0.6 - µs 20 + 0.1Cb[3] 300 ns 20 + 0.1Cb[3] 300 ns rise time of both SDA and SCL signals tr - 1000 tf fall time of both SDA and SCL signals - 300 tSP pulse width of spikes that must be suppressed by the input filter - 50 - 50 ns tv(Q) data output valid time - 200 - 200 ns tsu(D) data input set-up time 100 - 100 - ns th(D) data input hold time 1 - 1 - µs 8 - 8 - ns 0 - 0 - ns 400 - 400 - ns Port timing Reset timing tw(rst) reset pulse width trec(rst) reset recovery time trst reset time [4][5] [1] tVD;ACK = time for Acknowledgement signal from SCL LOW to SDA (out) LOW. [2] tVD;DAT = minimum time for SDA data output to be valid following SCL LOW. [3] Cb = total capacitance of one bus line in pF. [4] Resetting the device while actively communicating on the bus may cause glitches or errant STOP conditions. [5] Upon reset, the full delay will be the sum of trst and the RC time constant of the SDA bus. PCA9551_8 Product data sheet © NXP B.V. 2008. All rights reserved. Rev. 08 — 31 July 2008 15 of 26 PCA9551 NXP Semiconductors 8-bit I2C-bus LED driver with programmable blink rates ACK or read cycle START SCL SDA 30 % trst RESET 50 % 50 % trec(rst) 50 % tw(rst) trst LEDn 50 % LED off 002aac193 Fig 19. Definition of RESET timing SDA tr tBUF tf tHD;STA tSP tLOW SCL tHD;STA P S tSU;STA tHD;DAT tHIGH tSU;DAT Sr tSU;STO P 002aaa986 Fig 20. Definition of timing PCA9551_8 Product data sheet © NXP B.V. 2008. All rights reserved. Rev. 08 — 31 July 2008 16 of 26 PCA9551 NXP Semiconductors 8-bit I2C-bus LED driver with programmable blink rates protocol START condition (S) bit 7 MSB (A7) tSU;STA tLOW bit 6 (A6) tHIGH bit 0 (R/W) acknowledge (A) STOP condition (P) 1/f SCL SCL tBUF tr tf SDA tHD;STA tSU;DAT tVD;ACK tVD;DAT tHD;DAT tSU;STO 002aab175 Rise and fall times refer to VIL and VIH. Fig 21. I2C-bus timing diagram 12. Test information VDD PULSE GENERATOR VI VO RL 500 Ω VDD open VSS DUT RT CL 50 pF 002aab880 RL = load resistor for LEDn. RL for SDA and SCL > 1 kΩ (3 mA or less current). CL = load capacitance includes jig and probe capacitance. RT = termination resistance should be equal to the output impedance Zo of the pulse generators. Fig 22. Test circuitry for switching times PCA9551_8 Product data sheet © NXP B.V. 2008. All rights reserved. Rev. 08 — 31 July 2008 17 of 26 PCA9551 NXP Semiconductors 8-bit I2C-bus LED driver with programmable blink rates 13. Package outline SO16: plastic small outline package; 16 leads; body width 3.9 mm SOT109-1 D E A X c y HE v M A Z 16 9 Q A2 A (A 3) A1 pin 1 index θ Lp 1 L 8 e 0 detail X w M bp 2.5 5 mm scale DIMENSIONS (inch dimensions are derived from the original mm dimensions) UNIT A max. A1 A2 A3 bp c D (1) E (1) e HE L Lp Q v w y Z (1) mm 1.75 0.25 0.10 1.45 1.25 0.25 0.49 0.36 0.25 0.19 10.0 9.8 4.0 3.8 1.27 6.2 5.8 1.05 1.0 0.4 0.7 0.6 0.25 0.25 0.1 0.7 0.3 0.01 0.019 0.0100 0.39 0.014 0.0075 0.38 0.039 0.016 0.028 0.020 inches 0.010 0.057 0.069 0.004 0.049 0.16 0.15 0.05 0.244 0.041 0.228 0.01 0.01 0.028 0.004 0.012 θ o 8 o 0 Note 1. Plastic or metal protrusions of 0.15 mm (0.006 inch) maximum per side are not included. REFERENCES OUTLINE VERSION IEC JEDEC SOT109-1 076E07 MS-012 JEITA EUROPEAN PROJECTION ISSUE DATE 99-12-27 03-02-19 Fig 23. Package outline SOT109-1 (SO16) PCA9551_8 Product data sheet © NXP B.V. 2008. All rights reserved. Rev. 08 — 31 July 2008 18 of 26 PCA9551 NXP Semiconductors 8-bit I2C-bus LED driver with programmable blink rates TSSOP16: plastic thin shrink small outline package; 16 leads; body width 4.4 mm SOT403-1 E D A X c y HE v M A Z 9 16 Q (A 3) A2 A A1 pin 1 index θ Lp L 1 8 e detail X w M bp 0 2.5 5 mm scale DIMENSIONS (mm are the original dimensions) UNIT A max. A1 A2 A3 bp c D (1) E (2) e HE L Lp Q v w y Z (1) θ mm 1.1 0.15 0.05 0.95 0.80 0.25 0.30 0.19 0.2 0.1 5.1 4.9 4.5 4.3 0.65 6.6 6.2 1 0.75 0.50 0.4 0.3 0.2 0.13 0.1 0.40 0.06 8 o 0 o Notes 1. Plastic or metal protrusions of 0.15 mm maximum per side are not included. 2. Plastic interlead protrusions of 0.25 mm maximum per side are not included. OUTLINE VERSION SOT403-1 REFERENCES IEC JEDEC JEITA EUROPEAN PROJECTION ISSUE DATE 99-12-27 03-02-18 MO-153 Fig 24. Package outline SOT403-1 (TSSOP16) PCA9551_8 Product data sheet © NXP B.V. 2008. All rights reserved. Rev. 08 — 31 July 2008 19 of 26 PCA9551 NXP Semiconductors 8-bit I2C-bus LED driver with programmable blink rates HVQFN16: plastic thermal enhanced very thin quad flat package; no leads; 16 terminals; body 4 x 4 x 0.85 mm A B D SOT629-1 terminal 1 index area A A 1 E c detail X e1 C 1/2 e e 8 y y1 C v M C A B w M C b 5 L 9 4 e e2 Eh 1/2 e 1 12 terminal 1 index area 16 13 X Dh 0 2.5 5 mm scale DIMENSIONS (mm are the original dimensions) UNIT mm A(1) max. A1 b 1 0.05 0.00 0.38 0.23 c D (1) Dh E (1) Eh 0.2 4.1 3.9 2.25 1.95 4.1 3.9 2.25 1.95 e e1 0.65 1.95 e2 L v w y y1 1.95 0.75 0.50 0.1 0.05 0.05 0.1 Note 1. Plastic or metal protrusions of 0.075 mm maximum per side are not included. REFERENCES OUTLINE VERSION IEC JEDEC JEITA SOT629-1 --- MO-220 --- EUROPEAN PROJECTION ISSUE DATE 01-08-08 02-10-22 Fig 25. Package outline SOT629-1 (HVQFN16) PCA9551_8 Product data sheet © NXP B.V. 2008. All rights reserved. Rev. 08 — 31 July 2008 20 of 26 PCA9551 NXP Semiconductors 8-bit I2C-bus LED driver with programmable blink rates 14. Handling information Inputs and outputs are protected against electrostatic discharge in normal handling. However, to be completely safe you must take normal precautions appropriate to handling integrated circuits. 15. 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”. 15.1 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. 15.2 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 15.3 Wave soldering Key characteristics in wave soldering are: PCA9551_8 Product data sheet © NXP B.V. 2008. All rights reserved. Rev. 08 — 31 July 2008 21 of 26 PCA9551 NXP Semiconductors 8-bit I2C-bus LED driver with programmable blink rates • 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 15.4 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 26) 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 14 and 15 Table 14. SnPb eutectic process (from J-STD-020C) Package thickness (mm) Package reflow temperature (°C) Volume (mm3) < 350 ≥ 350 < 2.5 235 220 ≥ 2.5 220 220 Table 15. Lead-free process (from J-STD-020C) Package thickness (mm) Package reflow temperature (°C) Volume (mm3) < 350 350 to 2000 > 2000 < 1.6 260 260 260 1.6 to 2.5 260 250 245 > 2.5 250 245 245 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 26. PCA9551_8 Product data sheet © NXP B.V. 2008. All rights reserved. Rev. 08 — 31 July 2008 22 of 26 PCA9551 NXP Semiconductors 8-bit I2C-bus LED driver with programmable blink rates maximum peak temperature = MSL limit, damage level temperature minimum peak temperature = minimum soldering temperature peak temperature time 001aac844 MSL: Moisture Sensitivity Level Fig 26. Temperature profiles for large and small components For further information on temperature profiles, refer to Application Note AN10365 “Surface mount reflow soldering description”. 16. Abbreviations Table 16. Abbreviations Acronym Description CDM Charged-Device Model DSP Digital Signal Processor DUT Device Under Test ESD ElectroStatic Discharge GPIO General Purpose Input/Output HBM Human Body Model I2C-bus Inter-Integrated Circuit bus I/O Input/Output IC Integrated Circuit LED Light Emitting Diode MCU MicroController Unit MM Machine Model MPU MicroProcessor Unit POR Power-On Reset PWM Pulse Width Modulation; Pulse Width Modulator RC Resistor-Capacitor network SMBus System Management Bus PCA9551_8 Product data sheet © NXP B.V. 2008. All rights reserved. Rev. 08 — 31 July 2008 23 of 26 PCA9551 NXP Semiconductors 8-bit I2C-bus LED driver with programmable blink rates 17. Revision history Table 17. Revision history Document ID Release date Data sheet status Change notice Supersedes PCA9551_8 20080731 Product data sheet - PCA9551_7 Modifications: • • Section 1 “General description”: added (new) 5th paragraph Table 12 “Static characteristics”, sub-section “I/Os”: changed symbol “IL” to “ILI” (input leakage current) • Table 13 “Dynamic characteristics”, sub-section “Reset timing”: changed Min value for tw(rst) from “6 ns” to “8 ns” (for both Standard-mode and Fast-mode) • updated soldering information PCA9551_7 20070223 Product data sheet - PCA9551_6 PCA9551_6 20061107 Product data sheet - PCA9551_5 PCA9551_5 (9397 750 13726) 20041001 Product data sheet - PCA9551_4 PCA9551_4 (9397 750 11462) 20030505 Product data 853-2343 29858 (20030424) PCA9551_3 PCA9551_3 (9397 750 11155) 20030220 Product data 853-2343 29331 (20021220) PCA9551_2 PCA9551_2 (9397 750 10328) 20020927 Product data 853-2343 28878 (20020909) PCA9551_1 PCA9551_1 (9397 750 10104) 20020513 Product data - - PCA9551_8 Product data sheet © NXP B.V. 2008. All rights reserved. Rev. 08 — 31 July 2008 24 of 26 PCA9551 NXP Semiconductors 8-bit I2C-bus LED driver with programmable blink rates 18. Legal information 18.1 Data sheet status Document status[1][2] Product status[3] Definition Objective [short] data sheet Development This document contains data from the objective specification for product development. Preliminary [short] data sheet Qualification This document contains data from the preliminary specification. Product [short] data sheet Production This document contains the product specification. [1] Please consult the most recently issued document before initiating or completing a design. [2] The term ‘short data sheet’ is explained in section “Definitions”. [3] 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. 18.2 Definitions Draft — The document is a draft version only. The content is still under internal review and subject to formal approval, which may result in modifications or additions. NXP Semiconductors does not give any representations or warranties as to the accuracy or completeness of information included herein and shall have no liability for the consequences of use of such information. Short data sheet — A short data sheet is an extract from a full data sheet with the same product type number(s) and title. A short data sheet is intended for quick reference only and should not be relied upon to contain detailed and full information. For detailed and full information see the relevant full data sheet, which is available on request via the local NXP Semiconductors sales office. In case of any inconsistency or conflict with the short data sheet, the full data sheet shall prevail. 18.3 Disclaimers General — 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. 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 medical, military, aircraft, space or life support equipment, nor in applications where failure or malfunction of an NXP Semiconductors product can reasonably be expected to result in personal injury, death or severe property or environmental damage. NXP Semiconductors accepts no liability for inclusion and/or use of NXP Semiconductors products in such equipment or applications and therefore such inclusion and/or use is at the customer’s own risk. Applications — Applications that are described herein for any of these products are for illustrative purposes only. NXP Semiconductors makes no representation or warranty that such applications will be suitable for the specified use without further testing or modification. Limiting values — Stress above one or more limiting values (as defined in the Absolute Maximum Ratings System of IEC 60134) may cause permanent damage to the device. Limiting values are stress ratings only and operation of the device at these or any other conditions above those given in the Characteristics sections of this document is not implied. Exposure to limiting values for extended periods may affect device reliability. Terms and conditions of 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, including those pertaining to warranty, intellectual property rights infringement and limitation of liability, unless explicitly otherwise agreed to in writing by NXP Semiconductors. In case of any inconsistency or conflict between information in this document and such terms and conditions, the latter will prevail. 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. 18.4 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. 19. Contact information For more information, please visit: http://www.nxp.com For sales office addresses, please send an email to: [email protected] PCA9551_8 Product data sheet © NXP B.V. 2008. All rights reserved. Rev. 08 — 31 July 2008 25 of 26 PCA9551 NXP Semiconductors 8-bit I2C-bus LED driver with programmable blink rates 20. Contents 1 2 3 4 5 5.1 5.2 6 6.1 6.2 6.2.1 6.3 6.3.1 6.3.2 6.3.3 6.3.4 6.3.5 6.3.6 6.4 6.5 6.6 7 7.1 7.1.1 7.2 7.3 7.4 8 8.1 8.2 9 10 11 12 13 14 15 15.1 15.2 15.3 15.4 16 17 General description . . . . . . . . . . . . . . . . . . . . . . 1 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Ordering information . . . . . . . . . . . . . . . . . . . . . 2 Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Pinning information . . . . . . . . . . . . . . . . . . . . . . 3 Pinning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Pin description . . . . . . . . . . . . . . . . . . . . . . . . . 3 Functional description . . . . . . . . . . . . . . . . . . . 4 Device address . . . . . . . . . . . . . . . . . . . . . . . . . 4 Control register . . . . . . . . . . . . . . . . . . . . . . . . . 4 Control register definition . . . . . . . . . . . . . . . . . 5 Register descriptions . . . . . . . . . . . . . . . . . . . . 5 INPUT - Input register. . . . . . . . . . . . . . . . . . . . 5 PSC0 - Frequency Prescaler 0 . . . . . . . . . . . . . 5 PWM0 - Pulse Width Modulation 0 . . . . . . . . . . 6 PSC1 - Frequency Prescaler 1 . . . . . . . . . . . . . 6 PWM1 - Pulse Width Modulation 1 . . . . . . . . . . 6 LS0 to LS1 - LED selector registers . . . . . . . . . 7 Pins used as GPIOs . . . . . . . . . . . . . . . . . . . . . 7 Power-on reset . . . . . . . . . . . . . . . . . . . . . . . . . 7 External RESET . . . . . . . . . . . . . . . . . . . . . . . . 7 Characteristics of the I2C-bus. . . . . . . . . . . . . . 8 Bit transfer . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 START and STOP conditions . . . . . . . . . . . . . . 8 System configuration . . . . . . . . . . . . . . . . . . . . 8 Acknowledge . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Bus transactions . . . . . . . . . . . . . . . . . . . . . . . 10 Application design-in information . . . . . . . . . 11 Minimizing IDD when the I/Os are used to control LEDs . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Programming example . . . . . . . . . . . . . . . . . . 12 Limiting values. . . . . . . . . . . . . . . . . . . . . . . . . 12 Static characteristics. . . . . . . . . . . . . . . . . . . . 13 Dynamic characteristics . . . . . . . . . . . . . . . . . 15 Test information . . . . . . . . . . . . . . . . . . . . . . . . 17 Package outline . . . . . . . . . . . . . . . . . . . . . . . . 18 Handling information. . . . . . . . . . . . . . . . . . . . 21 Soldering of SMD packages . . . . . . . . . . . . . . 21 Introduction to soldering . . . . . . . . . . . . . . . . . 21 Wave and reflow soldering . . . . . . . . . . . . . . . 21 Wave soldering . . . . . . . . . . . . . . . . . . . . . . . . 21 Reflow soldering . . . . . . . . . . . . . . . . . . . . . . . 22 Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Revision history . . . . . . . . . . . . . . . . . . . . . . . . 24 18 18.1 18.2 18.3 18.4 19 20 Legal information . . . . . . . . . . . . . . . . . . . . . . Data sheet status . . . . . . . . . . . . . . . . . . . . . . Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . Disclaimers. . . . . . . . . . . . . . . . . . . . . . . . . . . Trademarks . . . . . . . . . . . . . . . . . . . . . . . . . . Contact information . . . . . . . . . . . . . . . . . . . . Contents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 25 25 25 25 25 26 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. 2008. All rights reserved. For more information, please visit: http://www.nxp.com For sales office addresses, please send an email to: [email protected] Date of release: 31 July 2008 Document identifier: PCA9551_8