Document
PCF8591
8-bit A/D and D/A converter
Rev. 7 — 27 June 2013
Product data sheet
1. General description
The PCF8591 is a single-chip, single-supply low-power 8-bit CMOS data acquisition device with four analog inputs, one analog output and a serial I2C-bus interface. Three address pins A0, A1 and A2 are used for programming the hardware address, allowing the use of up to eight devices connected to the I2C-bus without additional hardware. Address, control and data to and from the device are transferred serially via the two-line bidirectional I2C-bus.
The functions of the device include analog input multiplexing, on-chip track and hold function, 8-bit analog-to-digital conversion and an 8-bit digital-to-analog conversion. The maximum conversion rate is given by the maximum speed of the I2C-bus.
2. Features and benefits
Single power supply Operating supply voltage 2.5 V to 6.0 V Low standby current Serial input and output via I2C-bus I2C address selection by 3 hardware address pins Max sampling rate given by I2C-bus speed 4 analog inputs configurable as single ended or differential inputs Auto-incremented channel selection Analog voltage range from VSS to VDD On-chip track and hold circuit 8-bit successive approximation A/D conversion Multiplying DAC with one analog output.
3. Applications
Supply monitoring Reference setting Analog control loops
NXP Semiconductors
PCF8591
8-bit A/D and D/A converter
4. Ordering information
Table 1. Ordering information
Type number
Package
Name
PCF8591P
DIP16
PCF8591T
SO16
Description
plastic dual in-line package; 16 leads (300 mil)
plastic small outline package; 16 leads; body width 7.5 mm
Version SOT38-4
SOT162-1
4.1 Ordering options
Table 2. Ordering options
Product type number
Sales item (12NC) Orderable part number
PCF8591P
933768130112
PCF8591P,112
PCF8591T/2
935276541512
PCF8591T/2,512
935276541518
PCF8591T/2,518
IC revision 1 1 1
Delivery form
tube tube, dry pack tape and reel, dry pack, 13 inch
5. Marking
Table 3. Marking codes Type number PCF8591P PCF8591T
Marking code PCF8591P PCF8591T
PCF8591
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 7 — 27 June 2013
© NXP B.V. 2013. All rights reserved.
2 of 31
NXP Semiconductors
6. Block diagram
PCF8591
8-bit A/D and D/A converter
SCL SDA
A0 A1 A2
EXT VDD VSS
OSC
AIN0 AIN1 AIN2 AIN3
AOUT
I2C BUS INTERFACE
PCF8591
POWER ON RESET
OSCILLATOR
STATUS
DAC DATA ADC DATA
REGISTER REGISTER REGISTER
CONTROL LOGIC
ANALOGUE MULTIPLEXER
SAMPLE AND HOLD
SAMPLE AND HOLD
COMPARATOR
SUCCESSIVE APPROXIMATION REGISTER/LOGIC
DAC
Fig 1. Block diagram of PCF8591
7. Pinning information
VREF AGND
mbl821
7.1 Pinning
$,1 $,1 $,1 $,1
$ $ $ 966
3&)3
9'' $287 95() $*1' (;7 26& 6&/ 6'$
$,1 $,1 $,1 $,1
$ $ $ 966
3&)7
9'' $287 95() $*1' (;7 26& 6&/ 6'$
DDD
Fig 2.
Top view. For mechanical details, see Figure 22 on page 21.
Pin configuration for PCF8591P (DIP16)
DDD
Fig 3.
Top view. For mechanical details, see Figure 23 on page 22.
Pin configuration for PCF8591T (SO16)
PCF8591
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 7 — 27 June 2013
© NXP B.V. 2013. All rights reserved.
3 of 31
NXP Semiconductors
PCF8591
8-bit A/D and D/A converter
7.2 Pin description
Table 4. Symbol AIN0 AIN1 AIN2 AIN3 A0 A1 A2 VSS SDA SCL OSC EXT AGND VREF AOUT VDD
Pin description Pin 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
Description analog inputs (A/D converter)
hardware slave address
ground supply voltage I2C-bus serial data input and output I2C-bus serial clock input oscillator input/output external/internal switch for oscillator input analog ground supply voltage reference input analog output (D/A converter) supply voltage
PCF8591
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 7 — 27 June 2013
© NXP B.V. 2013. All rights reserved.
4 of 31
NXP Semiconductors
PCF8591
8-bit A/D and D/A converter
8. Functional description
8.1 Addressing
Each PCF8591 device in an I2C-bus system is activated by sending a valid address to the device. The address consists of a fixed part and a programmable part. The programmable part must be set according to the address pins A0, A1 and A2. The address is always sent as the first byte after the start condition in the I2C-bus protocol. The last bit of the address byte is the read/write-bit which sets the direction of the following data transfer (see Table 5 on page 13, Figure 15 on page 13 and Figure 16 on page 13).
8.2 Control byte
The second byte sent to a PCF8591 device is stored in its control register and is required to control the device function. The upper nibble of the control register is used for enabling the analog output, and for prog.