An 8-channel 12-bit SPI analog-to-digital converter in SOIC-16, the higher-resolution sibling of the MCP3008. Same pinout and interface, but 12 bits (4096 counts) instead of 10 for four times the resolution, sampling up to 100 k samples per second. The eight inputs read as eight single-ended channels or four pseudo-differential pairs against an external VREF, with separate analog and digital grounds for clean conversions. The four-wire SPI makes it a drop-in analog front end for any microcontroller, including the Raspberry Pi. Runs 2.7-5.5 V.

Pinout

Pin	Name	Type	Function
1	CH0	input	Analog input channel 0. Configurable as single-ended input or as IN+/IN- of a pseudo-differential pair with CH1. Input range VSS to VREF in single-ended mode.
2	CH1	input	Analog input channel 1. Configurable as single-ended input or as IN+/IN- of a pseudo-differential pair with CH0.
3	CH2	input	Analog input channel 2. Configurable as single-ended input or as IN+/IN- of a pseudo-differential pair with CH3.
4	CH3	input	Analog input channel 3. Configurable as single-ended input or as IN+/IN- of a pseudo-differential pair with CH2.
5	CH4	input	Analog input channel 4. Configurable as single-ended input or as IN+/IN- of a pseudo-differential pair with CH5.
6	CH5	input	Analog input channel 5. Configurable as single-ended input or as IN+/IN- of a pseudo-differential pair with CH4.
7	CH6	input	Analog input channel 6. Configurable as single-ended input or as IN+/IN- of a pseudo-differential pair with CH7.
8	CH7	input	Analog input channel 7. Configurable as single-ended input or as IN+/IN- of a pseudo-differential pair with CH6.
9	DGND	power_in	Digital ground return for internal digital circuitry. Connect to the system ground plane; keep separate return path from AGND where possible.
10	CS/SHDN	input	Active-low chip select / shutdown input. Falling edge initiates SPI communication and starts a conversion; driving high ends the conversion and places the device in low-power standby (IDDS ~0.5 uA typ). Must be pulled high between conversions.
11	DIN	input	SPI serial data input (MOSI). Used to load the start bit, single/differential select, and channel configuration bits into the device. Data is latched on the rising edge of CLK.
12	DOUT	output	SPI serial data output (MISO). Shifts out the 12-bit conversion result MSB first as the conversion takes place; data changes on the falling edge of CLK. High-impedance when CS is high.
13	CLK	input	SPI serial clock input. Initiates conversion and clocks each bit of the conversion out on DOUT. fCLK max 2.0 MHz at VDD=5V, 1.0 MHz at VDD=2.7V; effective clock rates below 10 kHz can affect linearity due to sample-cap charge loss.
14	AGND	power_in	Analog ground return for internal analog circuitry. Connect to the analog ground plane and tie to DGND at a single star point to minimise digital noise coupling into conversions.
15	VREF	input	External reference voltage input. Sets the analog input full-scale range. Valid range 0.25 V to VDD; typical current drain 100 uA (150 uA max). Reference noise/instability directly affects conversion accuracy.
16	VDD	power_in	Positive supply voltage, +2.7 V to +5.5 V. Typical operating current 320 uA at 5V (400 uA max, DOUT unloaded); bypass locally with a 0.1 uF ceramic to DGND/AGND.

Key specifications

Parameter	Value
Type	8-channel SAR ADC
Resolution	12-bit
Sample rate	100 ksps (at 5 V)
Inputs	8 single-ended or 4 pseudo-differential
Interface	SPI (up to 2 MHz)
Reference	external VREF pin
Supply voltage	2.7-5.5 V
Package	SOIC-16

Ordering variants

Same part, different packaging or reel option.

MCP3208-CI/SL (SOIC-16)
MCP3208-CI/P (PDIP-16)

CAD (KiCad official)

Symbol: Analog_ADC:MCP3208
Footprint: Package_SO:SOIC-16_3.9x9.9mm_P1.27mm
3D model: SOIC-16 (KiCad packages3D)

Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

Datasheet: Microchip Technology datasheet (40 pp, sha256 89bc1e17c35e2bb1, retrieved 2026-08-17, tier: manufacturer)
Extractor: ds2sf (Claude). Every pin and dimension is cited to a datasheet page; it refuses to fabricate.
CAD: KiCad official libraries (CC-BY-SA 4.0).

Datasheet PDF