User's Manual
Table Of Contents
- 1 Introduction
- Table of Contents
- 2 Description (continued)
- 3 Physical Characteristics
- 4 ELECTRICAL SPECIFICATIONS
- 5 System Description
- 5.1 Power Supplies
- 5.2 Receiver – Analog Section
- 5.3 Register Descriptions
- 5.4 Direct Commands From MCU to Reader
- 5.4.1 Command Codes
- 5.4.2 Reset
- 5.4.3 Transmission With CRC
- 5.4.4 Transmission Without CRC
- 5.4.5 Delayed Transmission With CRC
- 5.4.6 Delayed Transmission Without CRC
- 5.4.7 Transmission Next Slot
- 5.4.8 Receiver Gain Adjust
- 5.4.9 Test External RF (RSSI at RX input with TX OFF)
- 5.4.10 Test Internal RF (RSSI at RX input with TX ON)
- 5.4.11 Block Receiver
- 5.4.12 Enable Receiver
- 5.5 Reader Communication Interface
- 5.6 Parallel Interface Communication
- 5.7 Serial Interface Communication
- 5.8 External Power Amplifier Application
TRF7960
TRF7961
SLOU186F–AUGUST 2006–REVISED AUGUST 2010
www.ti.com
After the reader EN line is high, the other power modes are selected by control bits. The power mode
options and functions are listed in Table 5-5.
Table 5-5. Power Modes
Byte Option Bits Setting in Chip Status Control Register EN EN2 Functionality Current
Address
B7 B6 B5 B4 B3 B2 B1 B0
STBY RFON RF PWR REC ON
00 0 0 Complete power down <1 μA
00 0 1 VDD_X available 120 μA
SYS_CLK auxiliary frequency 60 kHz is ON
00 1 x x x 1 x All supply regulators active and in low power 1.5 mA
mode
13.56-MHz oscillator ON
SYS_CLK clock available
00 0 0 x 0 1 x All supply regulators active 3.5 mA
13.56-MHz oscillator ON
SYS_CLK clock available
00 0 0 x 1 1 x All supply regulators active 10 mA
13.56-MHz oscillator ON
SYS_CLK clock available
Receiver active
00 0 1 1 x 1 x All supply regulators active 70 mA
13.56-MHz oscillator ON (at 5 V)
SYS_CLK clock available
Receiver active
Transmitter active – half-power mode
00 0 1 0 x 1 x All supply regulators active 120 mA
13.56-MHz oscillator running (at 5 V)
SYS_CLK clock available
Receiver active
Transmitter active – full-power mode
During reader inactivity, the TRF7960/61 can be placed in power down-mode (EN = 0). The power down
can be complete (EN = 0, EN2 = 0) with no function running, or partial (EN = 0, EN2 = 1) where the
regulated supply (V
DD_X
) and auxiliary clock 60 kHz (SYS_CLK) are available to the MCU or other system
device.
When EN is set high (or on rising edge of EN2 and then confirmed by EN = 1), the supply regulators are
activated and the 13.56-MHz oscillator started. When the supplies are settled and the oscillator frequency
is stable, the SYS_CLK output is switched from the auxiliary frequency of 60 kHz to the selected
frequency derived from the crystal oscillator. At this point, the reader is ready to communicate and perform
the required tasks. The control system (MCU) can then write appropriate bits to the chip status control
register (address 00) and select the operation mode.
The STANDBY mode (bit 7 = 1 of register 00) is the active mode with the lowest current consumption. The
reader is capable of recovering from this mode to full operation in 100 μs.
The active mode with RF section disabled (bit 5 = 0 and bit 1 = 0 of register 00) is the next active mode
with low power consumption. The reader is capable of recovering from this mode to full operation in 25 μs.
The active mode with only the RF receiver section active (bit 1 = 1 of register 00) can be used to measure
the external RF field (as described in RSSI measurements paragraph) if reader-to-reader anticollision is
implemented.
The active mode with the entire RF section active (bit 5 = 1 of register 00) is the normal mode used for
transmit and receive operations.
14 System Description Copyright © 2006–2010, Texas Instruments Incorporated
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