1.1.1 The 12-Bit ADC Performance is Outside the Data Sheet's Specifications

The 12-bit ADC performance is outside the data sheet's ADC specifications. When used as a 12-bit ADC, the possible issues are:

High offset error:
- up to a maximum of ±25 LSb at 25°C
- up to a maximum of ±30 LSb at -40°C, 85°C, and 125°C
High DNL error:
- up to a maximum of +6.0/-4.0 LSb
Multiple missing codes:
- up to a maximum of 20 missing codes

Users should evaluate the 12-bit ADC performance in their application using the suggested work around. See table below for guidance specifications.

Reduced bit resolution specifications can be derived by dividing, as appropriate. For instance, 10-bit guidance is obtained by dividing the parameters in the table below by four.

Table 1-1. ADC Characteristics
Standard Operating Conditions (unless otherwise stated)
Param  No.	Sym.	Characteristics	Min.	Typ†	Max.	Units	Conditions
A01	N_R	Resolution	—	—	12	bit	ΔV_REF ≥ 5.0V
A02	E_IL	Integral Linearity Error	—	—	±10	LSb	ΔV_REF ≥ 5.0V
A04	E_DL	Differential Linearity Error	—	—	+6.0/-4.0	LSb	ΔV_REF ≥ 5.0V
A06	E_OFF	Offset Error	— —	— —	±25 ±30	LSb LSb	ΔV_REF ≥ 5.0V, 25°C ΔV_REF ≥ 5.0V, -40°C, 85°C, 125°C
A07	E_GN	Gain Error	—	—	±15	LSb	ΔV_REF ≥ 5.0V
A10	—	Monotonicity⁽¹⁾	—	—	—	—	V_SS ≤ V_AIN ≤ V_REF
A20	ΔV_REF	Reference Voltage Range (V_REFH - V_REFL)	3	—	AV_DD - AV_SS	V
A21	V_REFH	Reference Voltage High	AV_SS + 3.0V	—	AV_DD + 0.3V	V
A22	V_REFL	Reference Voltage Low	AV_SS - 0.3V	—	AV_DD - 3.0V	V
A25	V_AIN	Analog Input Voltage	V_REFL	—	V_REFH	V
Note: The ADC conversion result never decreases with an increase in the input voltage.

Work around

Calibrate for offset in Single-Ended mode by connecting a positive ADC input to ground and taking the reading. This will be the offset of the device and can be used to compensate for the subsequent readings on the actual inputs.

Affected Silicon Revisions


A2	A3	A4	A6	A7
X	X	X	X	X