PIC16F636-E/ST Microchip Technology, PIC16F636-E/ST Datasheet - Page 112

• Manufacturer Part Number: PIC16F636-E/ST
• Description: IC MCU FLASH 2KX14 14TSSOP
• Manufacturer: Microchip Technology
• Series: PIC® 16Fr

Specifications of PIC16F636-E/ST

• Core Processor: PIC
• Core Size: 8-Bit
• Speed: 20MHz
• Peripherals: Brown-out Detect/Reset, LVD, POR, WDT
• Number Of I /o: 11
• Program Memory Size: 3.5KB (2K x 14)
• Program Memory Type: FLASH
• Ram Size: 128 x 8
• Voltage - Supply (vcc/vdd): 2 V ~ 5.5 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 14-TSSOP
• For Use With: AC162057 - MPLAB ICD 2 HEADER 14DIP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Data Converters: -
• Connectivity: -

PIC12F635/PIC16F636/639
11.26 Factory Calibration
Microchip
device-to-device variation in standby current, internal
timing and sensitivity, as well as channel-to-channel
sensitivity variation.
11.27 De-Q’ing of Antenna Circuit
When the transponder is close to the base station, the
transponder coil may develop coil voltage higher than
V
detects the strong near field signal through the AGC
control, and de-Q’ing the antenna circuit to reduce the
input signal amplitude.
FIGURE 11-8:
DS41232D-page 110
DE
V
_
Legend:
BAT
Q
. This condition is called “near field”. The AFE
calibrates
D
D
C
BLOCK
BLOCK
D
C
R
POOL
D
R
FLAT
COM
COM
LIM
LIM
LF FIELD POWERING AND BATTERY BACK-UP EXAMPLE
= LCCOM charging capacitor.
= Pool capacitor (or battery back-up capacitor), charges in field and powers device.
= Battery protection from reverse charge.
= Field rectifier diodes.
= Voltage limiting diode, may be required to limit V
= C
= Current limiting resistor, required for air coil in strong fields.
the
Schottky for low forward bias drop.
D
COM
LIM
AFE
discharge path.
V
DD
to
C
POOL
reduce
D
D
the
FLAT
FLAT
1
2
Air Coil
L
X
11.28 Battery Back-up and Batteryless
The device supports both battery back-up and
batteryless operation by the addition of external
components, allowing the device to be partially or
completely powered from the field.
Figure 11-8 shows an example of the external circuit for
the battery back-up.
Note:
R
L
C
Y
COM
X
R
LIM
Operation
DD
Voltage on L
voltage must not exceed the maximum LC
input voltage.
C
C
voltage when in strong fields.
COM
Y
L
Z
© 2007 Microchip Technology Inc.
CCOM
C
Z
LCCOM
combined with coil input
LCX
LCY
LCZ