JAJSGM3 December 2018 DAC8742H
PRODUCTION DATA.
PIN | I/O | DESCRIPTION | |||
---|---|---|---|---|---|
NAME | NO. | ||||
XEN | 2 | Digital Input | Crystal Oscillator Enable. Logic low on this pin enables the crystal oscillator circuit; in this mode an external crystal is required. Logic high on this pin disables the internal crystal oscillator circuit; in this mode an external CMOS clock or the internal oscillator are required. No digital input pin should be left floating. | ||
CLKO | 3 | Digital Output | Clock Output. If using the internal oscillator or an external crystal, this pin can be configured as a clock output. | ||
CLK_CFG0 | 4 | Digital Input | Clock Configuration Pin. This pin is used to configure the input/output clocking scheme. No digital input pin should be left floating. | ||
CLK_CFG1 | 5 | Digital Input | Clock Configuration Pin. This pin is used to configure the input/output clocking scheme. No digital input pin should be left floating. | ||
RST | 6 | Digital Input | Reset. Logic low on this pin places the DAC8742H into power-down mode and resets the device. Logic high returns the device to normal operation. No digital input pin should be left floating. | ||
CD / IRQ | 7 | Digital Output | UART Mode | HART Mode | Carrier detect. A logic high on this pin indicates a valid carrier is present. |
FF / PA Mode | While not transmitting, a logic high on this pin indicates a valid carrier is present. While transmitting, a logic high on this pin indicates that the jabber inhibitor has triggered. | ||||
SPI Mode | Digital Interrupt. The interrupt can be configured as edge sensitive or level sensitive with positive or negative polarity, as set by the CONTROL register. Events that trigger an interrupt are controlled by the Modem IRQ Mask register. | ||||
IF_SEL | 9 | Digital Input | Interface select. A logic high on this pin configures the device for SPI mode. A logic low on this pin configures the device for UART mode. An internal pull-down resistor is included. No digital input pin should be left floating. | ||
UART_IN /
CS |
10 | Digital Input | UART Mode | UART data input. | |
SPI Mode | SPI chip-select. Data bits are clocked into the serial shift register when CS is low. When CS is high, SDO is in a high-impedance state and data on SDI are ignored. No digital input pin should be left floating. No digital input pin should be left floating. | ||||
UART_RTS /
SCLK |
11 | Digital Input,
Digital Output |
UART Mode | HART Mode | Request to send a logic high on this pin enables the demodulator and disables the modulator. A logic low on this pin enables the modulator and disables the demodulator. No digital input pin should be left floating. |
FF / PA Mode | This pin reports transmit FIFO threshold information as programmed by the packet initiation code. | ||||
SPI Mode | SPI clock. Data can be transferred at rates up to 12.5MHz. Schmitt-Trigger logic input. | ||||
DUPLEX / SDI | 12 | Digital Output | UART Mode | Digital input. Logic high enables full-duplex, or internal loop-back, test mode. | |
SPI Mode | SPI data input. Data is clocked into the 24-bit input shift register on the falling edge of the serial clock input. Schmitt-Trigger logic input. | ||||
UART_OUT /
SDO |
13 | Digital Output | UART Mode | UART data output. | |
SPI Mode | SPI data output. Data is valid on the falling edge of SCLK. | ||||
IOVDD | 14 | Supply | Interface supply. Supply voltage for digital input and output circuitry. This voltage sets the logical thresholds for the digital interface. | ||
GND | 15 | Supply | Digital ground. Ground reference voltage for all digital circuitry of the device. | ||
REG_CAP | 18 | Analog Output | Capacitor for internal regulator. | ||
MOD_OUT | 19 | Analog Output | Modem output. FSK output sinusoid in HART mode or Manchester coded data stream in FOUNDATION Fieldbus and PROFIBUS PA modes. Requires parallel capacitance of 5-22 nF in HART mode or 0-100 pF in FOUNDATION Fieldbus and PROFIBUS PA mode for stability. | ||
REF | 20 | Analog Input
or Output |
When the internal reference is enabled this pin outputs the internal reference voltage. When the internal reference is disabled, this is the external 2.5V reference input. | ||
MOD_IN | 21 | Analog Input | HART FSK input or FOUNDATION Fieldbus and PROFIBUS PA Manchester coded data stream input. If an external filter is used, do not connect this pin. | ||
MOD_INF | 22 | Analog Input | If using the internal band-pass filter, connect 680 pF to this pin or 120 pF in FOUNDATION Fieldbus and PROFIBUS PA modes. If using an external filter, connect the output of that filter to this pin. | ||
AVDD | 23 | Supply | Power supply. | ||
GND | 26 | Supply | Analog ground. Ground reference voltage for power supply input. | ||
X2 | 27 | Analog Input | Crystal stimulus. | ||
X1 | 28 | Analog Input | Crystal/Clock input. | ||
GND | 29 | Supply | Digital ground. Ground reference voltage for all digital circuitry of the device. | ||
REF_EN | 30 | Digital Input | Reference enable. Logic high enables the internal 1.5V reference. No digital input pin should be left floating. | ||
BPF_EN | 31 | Digital Input | Filter enable. A logic high enables the internal band-pass filter. No digital input pin should be left floating. | ||
NC | 1, 8, 16, 17,
24, 25, 32 |
– | Do not connect these pins. |