6 Pin Configuration and Functions

Figure 6-1 RHA Package, 40-Pin VQFN, Top View

Figure 6-2 PWP Package, 24-Pin HTSSOP, Top View

Table 6-1 Pin Functions

PIN			TYPE	DESCRIPTION
NAME	RHA (VQFN)	PWP (HTSSOP)	TYPE	DESCRIPTION
ALARM	2	3	Digital output	Alarm pin. Open drain output. External pullup resistor required (10 kΩ). The pin goes low (active) when the ALARM condition is detected (open circuit, over temperature, timeout, and so on).
AVDD	36	24	Supply input	Positive analog power supply.
BOOST	27	20	Analog output	Boost pin. External transistor connection (optional).
CAP1	28	21	Analog input	Connection for output filtering capacitor (optional).
CAP2	29	22	Analog input	Connection for output filtering capacitor (optional).
CLR	5	6	Digital input	Clear input. Logic high on this pin causes the part to enter CLEAR state. Active high.
DIN	8	9	Digital input	Serial data input. Data are clocked into the 24-bit input shift register on the rising edge of the serial clock input. Schmitt-Trigger logic input.
DVDD	39	2	Supply input or output	Digital power supply. Can be input or output, depending on DVDD-EN pin.
DVDD-EN	23	16	Digital input	Internal power-supply enable pin. Connect this pin to GND to disable the internal supply, or leave this pin unconnected to enable the internal supply. When this pin is connected to GND, an external supply must be connected to the DVDD pin.
GND	12, 13, 14, 15, 37	1, 11, 12	Supply input	Ground reference point for all analog circuitry of the device.
GND	3, 4	4, 5	Supply input	Ground reference point for all digital circuitry of the device.
HART-IN	24	17	Analog input	Input pin for HART modulation.
IOUT	26	19	Analog output	Current output pin
ISET-R	16	13	Analog input	Connection pin for external precision resistor (15 kΩ). See Section 8 of this data sheet.
LATCH	6	7	Digital input	Load DAC registers input. A rising edge on this pin loads the input shift register data into the DAC data and control registers and updates the DAC output.
NC	1, 10, 11, 19, 20, 21, 22, 30, 31, 32, 33, 34, 35, 38, 40	23	—	No connection.
R3-SENSE	25	18	Analog output	This pin is used as a monitoring feature for the output current. The voltage measured between the R3-SENSE pin and the BOOST pin is directly proportional to the output current.
REFOUT	17	14	Analog output	Internal reference output. Connects to REFIN when using internal reference.
REFIN	18	15	Analog input	Reference input
SCLK	7	8	Digital input	Serial clock input of the SPI. Data can be transferred at rates up to 30 MHz. Schmitt-Trigger logic input.
SDO	9	10	Digital output	Serial data output. Data are valid on the rising edge of SCLK.
Thermal Pad	—	—	Supply input	The thermal pad is internally connected to GND. For enhanced thermal performance, thermally connect the pad to a copper plane. The pad can be electrically connected to the same potential as the GND pin or left electrically unconnected provided a supply connection is made at the GND pin.