Block Diagram - Holtek BC45B4523 Manual

amplitudes as low as 1mV without distorting the data
pp
integrity. The receiver filters can be selected optionally
either to a predefined band in accordance with the
generic required standard setup, or to an arbitrarily
defined combination which gives flexibility to cope with
various antenna variations/parameters. The baseband
circuits permit the inbound/outbound configuration to
accept various forms of customized protocols, incoming
to the chip and outgoing to the external RF circuitry in
the application specific-design system.
The transmitter is capable of accepting a wide range of
operating supply voltages to serve various applications,
e.g., 5V for base stations or desktop readers, and 3.3V
for handheld devices. The transmission controller
is entirely used to support all operation status and
requests, including FIFO status full/high/low and
transmission complete flag. The transmitter drivers
support a wide range of power supply voltages from
2.7V to 5.5V. A high drive current up to 250mA is
guaranteed for demanding item-level mid-range reader

Block Diagram

A_VDD A_VSS XTAL1 XTAL2
Receiver
TA
Voltage
VMID
Reference
RX ENV Amp
Transmitter
T_VDD
TX1
TX2
T_VSS
Rev. 1.20
designs. The dual high-powered transmitters can be
flexibly configured in various configurations, e.g.
differential driving, single-ended driving and a mode
to drive an external Class-E amplifier for improving
the drive strength in the gate antenna setup.
The BC45B4523 contains efficient power saving
modes: Hard Power Down, Soft Power Down,
Standby and low-power Card Detection modes. The
low-power Card Detection mode allows the device
to not operate at full power continuously. The device
periodically detects external card. If an external card
is detected, interrupt signal will be sent to MCU to
wake up the system.
To facilitate operation of the companion microcontroller,
the BC45B4523 is fully equipped with on-chip
peripheral support devices such as an RF-trig timer,
a host interrupt generator and a clock divider. The
BC45B4523 is offered in a QFN package with excellent
heat dissipation when self-mounted on PCB.
VREG_IN VREG_OUT
Regulator
Digital
3V3
Registers
CLK13M
Low Freq.
OSC
Power Mode
POR
Control
RF
Amplitude
Detector
CLK16k
WkUp
Data
Timer
Evaluator
Bit Level CODEC
Generator
Encryption
Engine
Wake Up Controller /
Frame CODEC
Functional Block Diagram
2
D_VDD
Regulator
1V6
Interface
Control ( SPI )
IRQ Controller
Program Timer
CRC
FIFO
State Machine /
Flow Control
BC45B4523
IO_VDD
SCLK
MOSI
MISO
NCS
IRQ
DIG
I/O
TD
RSTPD
D_VSS
October 28, 2020