ADE5569ASTZF62 Analog Devices Inc, ADE5569ASTZF62 Datasheet - Page 126

• Manufacturer Part Number: ADE5569ASTZF62
• Description: IC METER/8052/RTC/LCD DRV 64LQFP
• Manufacturer: Analog Devices Inc

Specifications of ADE5569ASTZF62

• Applications: Energy Measurement
• Core Processor: 8052
• Program Memory Type: FLASH (62kB)
• Controller Series: ADE55xx
• Ram Size: 2.25K x 8
• Interface: I²C, SPI, UART
• Number Of I /o: 20
• Voltage - Supply: 3.135 V ~ 3.465 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 64-LQFP
• Ic Function: Single Phase Energy Measurement IC
• Supply Voltage Range: 3.13V To 3.46V, 2.4V To 3.7V
• Operating Temperature Range: -40°C To +85°C
• Digital Ic Case Style: LQFP
• No. Of Pins: 64
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

ADE5166/ADE5169/ADE5566/ADE5569
RTC CRYSTAL COMPENSATION
The RTC provides registers to compensate for the tolerance of
the crystal frequency and its variation over temperature. Up to
±248 ppm frequency error can be calibrated out by the RTC
circuitry. The compensation is fully digital and implemented
by adding or subtracting pulses from the crystal clock signal.
The resolution of the RTC nominal compensation SFR
(RTCCOMP, Address 0xF6) is ±2 ppm/LSB, or 0.17 sec/day/LSB.
The RTC compensation circuitry adds the RTC temperature com-
pensation SFR (TEMPCAL, Address 0xF7) and the RTCCOMP
SFR to determine how much compensation is required. The sum
of these two registers is limited to ±248 ppm, or 42.85 sec/day.
RTC Calibration
The nominal crystal frequency can be calibrated by adjusting
the RTCCOMP SFR so that the clock going into the RTC is
precisely 32.768 kHz at 25°C.
Calibration Flow
An RTC calibration pulse output is on up to four pins configured
by the four LSBs in the RTC calibration configuration register
(RTC_CAL, Address 0x0F). Enable the RTC output by setting
the CAL_EN bit (RTC_CAL[6]).
The RTC calibration is accurate to within ±2 ppm over a 30.5 sec
window in all operational modes: PSM0, PSM1, and PSM2. Two
output frequencies are offered for the normal RTC mode: 1 Hz
with the FSEL bits = 00 and 512 Hz with the FSEL bits = 01
(RTC_CAL[5:4]).
A shorter window of 0.244 sec is offered for fast calibration during
PSM0 or PSM1 mode. Two output frequencies are offered for this
RTC calibration output mode: 500 Hz with the FSEL bits = 10 and
16 kHz with the FSEL bits = 11 (RTC_CAL[5:4]). Note that for
the 0.244 sec calibration window, the RTC is clocked 125 times
Rev. C | Page 126 of 156
faster than in the normal mode, resulting in timekeeping registers
that represent seconds/125, minutes/125, and hours/125, instead
of seconds, minutes, and hours. Therefore, this mode should be
used for calibration only.
Table 138. RTC Calibration Options
Option
Normal Mode 0
Normal Mode 1
Calibration Mode 0
Calibration Mode 1
When no RTC compensation is applied, with RTCCOMP and
TEMPCAL equal to zero, the nominal compensation required
to account for the error in the external crystal can be deter-
mined. In this case, it is not necessary to wait for an entire
calibration window to determine the error in the pulse output.
Calculating the error in frequency between two consecutive
pulses on the RTC calibration pin is sufficient.
The value to write to the RTCCOMP SFR is calculated from the
% error or seconds per day error on the frequency output. Each
bit of the RTCCOMP SFR represents 2 ppm of correction, where
1 sec/day error is equal to 11.57 ppm.
During calibration, user software writes the current time to the
RTC. Refer to the Access to Internal RTC Registers section for
more information on how to read and write to the RTC time-
keeping registers.
RTCCOMP = 5000 × (% Error)
RTCCOMP =
2
×
11
FSEL Bits
00
01
10
11
1
.
57
× (second/day Error)
Calibration
Window (sec)
30.5
30.5
0.244
0.244
f
(Hz)
1
512
500
16,000
RTCCAL