C8051F587-IMR Silicon Labs, C8051F587-IMR Datasheet - Page 60
![no-image](/images/no-image-200.jpg)
C8051F587-IMR
Manufacturer Part Number
C8051F587-IMR
Description
8-bit Microcontrollers - MCU 50 MIPS 96 kB 8 kB SPI 2xUART
Manufacturer
Silicon Labs
Datasheet
1.C8051F585-IQR.pdf
(356 pages)
Specifications of C8051F587-IMR
Rohs
yes
Core
8051
Data Bus Width
8 bit
Processor Series
C8051
- Current page: 60 of 356
- Download datasheet (3Mb)
C8051F58x/F59x
6.3. Selectable Gain
ADC0 on the C8051F58x/F59x family of devices implements a selectable gain adjustment option. By writ-
ing a value to the gain adjust address range, the user can select gain values between 0 and 1.016.
For example, three analog sources to be measured have full-scale outputs of 5.0 V, 4.0 V, and 3.0 V,
respectively. Each ADC measurement would ideally use the full dynamic range of the ADC with an internal
voltage reference of 1.5 V or 2.2 V (set to 2.2 V for this example). When selecting the first source (5.0 V
full-scale), a gain value of 0.44 (5 V full scale x 0.44 = 2.2 V full scale) provides a full-scale signal of 2.2 V
when the input signal is 5.0 V. Likewise, a gain value of 0.55 (4 V full scale x 0.55 = 2.2 V full scale) for the
second source and 0.73 (3 V full scale x 0.73 = 2.2 V full scale) for the third source provide full-scale ADC0
measurements when the input signal is full-scale.
Additionally, some sensors or other input sources have small part-to-part variations that must be
accounted for to achieve accurate results. In this case, the programmable gain value could be used as a
calibration value to eliminate these part-to-part variations.
6.3.1. Calculating the Gain Value
The ADC0 selectable gain feature is controlled by 13 bits in three registers. ADC0GNH contains the 8
upper bits of the gain value and ADC0GNL contains the 4 lower bits of the gain value. The final GAINADD
bit (ADC0GNA.0) controls an optional extra 1/64 (0.016) of gain that can be added in addition to the
ADC0GNH and ADC0GNL gain. The ADC0GNA.0 bit is set to 1 after a power-on reset.
The equivalent gain for the ADC0GNH, ADC0GNL and ADC0GNA registers is as follows:
Where:
GAIN is the 12-bit word of ADC0GNH[7:0] and ADC0GNL[7:4]
GAINADD is the value of the GAINADD bit (ADC0GNA.0)
gain is the equivalent gain value from 0 to 1.016
60
Equation 6.2. Equivalent Gain from the ADC0GNH and ADC0GNL Registers
Px.x
Figure 6.5. ADC0 Equivalent Input Circuit
gain
=
RC
MUX Select
Input
GAIN
-------------- -
4096
= R
MUX
+
Rev. 1.2
* C
GAINADD
R
MUX
SAMPLE
----- -
64
1
C
SAMPLE
Related parts for C8051F587-IMR
Image
Part Number
Description
Manufacturer
Datasheet
Request
R
![CP2102EK](/photos/9/3/90395/cp2102ek_tmb.jpg)
Part Number:
Description:
KIT EVALUATION FOR CP2102
Manufacturer:
Silicon Laboratories Inc
Datasheet:
![CP2103EK](/photos/9/6/90669/cp2103ek_tmb.jpg)
Part Number:
Description:
KIT EVAL FOR CP2103 USB TO UART
Manufacturer:
Silicon Laboratories Inc
Datasheet:
![CP2201EK](/photos/9/9/90977/cp2201ek_tmb.jpg)
Part Number:
Description:
KIT EVAL FOR CP2201 ETH CTRLR
Manufacturer:
Silicon Laboratories Inc
Datasheet:
![CAPTOUCHSENSEDC](/photos/9/20/92001/captouchsensedc_tmb.jpg)
Part Number:
Description:
DAUGHTER CARD CAP TOUCH SENSE
Manufacturer:
Silicon Laboratories Inc
Datasheet:
![CAPTOUCHSENSESK](/photos/9/20/92002/captouchsensesk_tmb.jpg)
Part Number:
Description:
KIT STARTER CAP TOUCH SENSE
Manufacturer:
Silicon Laboratories Inc
Datasheet:
![C8051F320DK](/photos/9/20/92068/c8051f320dk_tmb.jpg)
Part Number:
Description:
DEV KIT FOR C8051F320/F321
Manufacturer:
Silicon Laboratories Inc
Datasheet:
![C8051F120DK](/photos/9/20/92070/c8051f120dk_tmb.jpg)
Part Number:
Description:
DEVKIT-F120/21/22/23/24/25/26/27
Manufacturer:
Silicon Laboratories Inc
Datasheet:
![C8051F310DK](/photos/9/23/92300/c8051f310dk_tmb.jpg)
Part Number:
Description:
DEV KIT FOR C8051F310/F311
Manufacturer:
Silicon Laboratories Inc
Datasheet:
![C8051F226DK](/photos/9/23/92302/c8051f226dk_tmb.jpg)
Part Number:
Description:
DEV KIT F220/221/226/230/231/236
Manufacturer:
Silicon Laboratories Inc
Datasheet:
![C8051F300DK](/photos/9/23/92305/c8051f300dk_tmb.jpg)
Part Number:
Description:
DEV KIT F300/301/302/303/304/305
Manufacturer:
Silicon Laboratories Inc
Datasheet:
![C8051F330DK](/photos/9/23/92306/c8051f330dk_tmb.jpg)
Part Number:
Description:
DEV KIT FOR C8051F330/F331
Manufacturer:
Silicon Laboratories Inc
Datasheet:
![C8051F005DK](/photos/9/23/92307/c8051f005dk_tmb.jpg)
Part Number:
Description:
DEV KIT FOR F005/006/007
Manufacturer:
Silicon Laboratories Inc
Datasheet:
![C8051F020DK](/photos/9/23/92314/c8051f020dk_tmb.jpg)
Part Number:
Description:
DEV KIT FOR F020/F021/F022/F023
Manufacturer:
Silicon Laboratories Inc
Datasheet:
![C8051F340DK](/photos/9/23/92323/c8051f340dk_tmb.jpg)
Part Number:
Description:
KIT DEV FOR C8051F34X
Manufacturer:
Silicon Laboratories Inc
Datasheet:
![C8051F410DK](/photos/9/23/92324/c8051f410dk_tmb.jpg)
Part Number:
Description:
KIT DEV FOR C8051F41X
Manufacturer:
Silicon Laboratories Inc
Datasheet: