Electronic Components Datasheet Search |
|
MAX7315 Datasheet(PDF) 7 Page - Maxim Integrated Products |
|
MAX7315 Datasheet(HTML) 7 Page - Maxim Integrated Products |
7 / 27 page ports register latches the current-input logic level of the affected eight ports. Transition detection allows all ports configured as inputs to be monitored for changes in their logic status. The action of reading the input ports register samples the corresponding 8 port bits’ input condition. This sample is continuously compared with the actual input conditions. A detected change in input condition causes the INT/O8 interrupt output to go low, if configured as an interrupt output. The interrupt is cleared either automatically if the changed input returns to its original state, or when the input ports reg- ister is read. The INT/O8 pin can be configured as either an interrupt output or as a 9th output port with the same static or blink controls as the other eight ports (Table 4). Port Output Control and LED Blinking The blink phase 0 register sets the output logic levels of the eight ports P0–P7 (Table 8). This register controls the port outputs if the blink function is disabled. A duplicate register, the blink phase 1 register, is also used if the blink function is enabled (Table 9). In blink mode, the port outputs can be flipped between using the blink phase 0 register and the blink phase 1 regis- ter using software control (the blink flip flag in the con- figuration register) (Table 4). PWM Intensity Control The MAX7315 includes an internal oscillator, nominally 32kHz, to generate PWM timing for LED intensity con- trol. PWM intensity control can be enabled on an out- put-by-output basis, allowing the MAX7315 to provide any mix of PWM LED drives and glitch-free logic out- puts (Table 10). PWM can be disabled entirely, in which case all output ports are static and the MAX7315 operating current is lowest because the internal oscilla- tor is turned off. PWM intensity control uses a 4-bit master control and 4 bits of individual control per output (Tables 13, 14). The 4-bit master control provides 16 levels of overall intensi- ty control, which applies to all PWM-enabled output ports. The master control sets the maximum pulse width from 1/15 to 15/15 of the PWM time period. The individual settings comprise a 4-bit number further reducing the duty cycle to be from 1/16 to 15/16 of the time window set by the master control. For applications requiring the same PWM setting for all output ports, a single global PWM control can be used instead of all the individual controls to simplify the con- trol software and provide 240 steps of intensity control (Tables 10 and 13). Standby Mode When the serial interface is idle and the PWM intensity control is unused, the MAX7315 automatically enters standby mode. If the PWM intensity control is used, the operating current is slightly higher because the internal PWM oscillator is running. When the serial interface is active, the operating current also increases because the MAX7315, like all I2C slaves, has to monitor every transmission. Serial Interface Serial Addressing The MAX7315 operates as a slave that sends and receives data through an I2C-compatible 2-wire inter- face. The interface uses a serial data line (SDA) and a serial clock line (SCL) to achieve bidirectional commu- nication between master(s) and slave(s). A master (typ- ically a microcontroller) initiates all data transfers to and from the MAX7315 and generates the SCL clock that synchronizes the data transfer (Figure 2). The MAX7315 SDA line operates as both an input and an open-drain output. A pullup resistor, typically 4.7k Ω, is required on SDA. The MAX7315 SCL line operates 8-Port I/O Expander with LED Intensity Control and Interrupt _______________________________________________________________________________________ 7 Figure 2. 2-Wire Serial Interface Timing Details SCL SDA tR tF tBUF START CONDITION STOP CONDITION REPEATED START CONDITION START CONDITION tSU,STO tHD,STA tSU,STA tHD,DAT tSU,DAT tLOW tHIGH tHD,STA |
Similar Part No. - MAX7315 |
|
Similar Description - MAX7315 |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.COM |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Datasheet Upload | Contact us | Privacy Policy | Link Exchange | Manufacturer List All Rights Reserved©Alldatasheet.com |
Russian : Alldatasheetru.com | Korean : Alldatasheet.co.kr | Spanish : Alldatasheet.es | French : Alldatasheet.fr | Italian : Alldatasheetit.com Portuguese : Alldatasheetpt.com | Polish : Alldatasheet.pl | Vietnamese : Alldatasheet.vn Indian : Alldatasheet.in | Mexican : Alldatasheet.com.mx | British : Alldatasheet.co.uk | New Zealand : Alldatasheet.co.nz |
Family Site : ic2ic.com |
icmetro.com |