HOLTEK BC7161

Bluetooth Beacon technology leverages the BLE Advertising feature to support emerging applications such as indoor navigation and healthcare. Advertising packets are transmitted on channels 37, 38, and 39, avoiding interference from WiFi channels in the ISM band. The BC7161 is suited for Beacon devices in various proximity sensing applications.

The BC7161 is a low-cost 2.4GHz BLE Beacon transmitter. A complete Beacon device can be built with just an external 32MHz crystal oscillator (XO), an MCU, and a few ceramic capacitors. Output power can be configured from -10dBm to +5dBm in different levels based on application requirements. Even in the low-cost 8-pin SOP-EP package, it can achieve a maximum output power of +8dBm with a current consumption of only 24mA.

• GFSK modulation (BT=0.5), 1Mbps data rate, BLE compliant
• Operating frequency: 2402/2426/2480MHz
• Operating voltage range: 2.0V~3.6V
• Programmable TX power — High-power matching: -10/-5/-2/+5dBm (max. +8dBm); Low-power matching: -10/-5/0/+2dBm (max. +5dBm)
• Low current consumption — Deep sleep current: 0.35uA ♦ TX current: 19mA @ 5dBm TX power ♦ TX current: 12mA @ -5dBm TX power
• 32MHz crystal oscillator support
• FCC/ETSI compliant
• Package types: 8-pin SOP-EP, 10-pin MSOP-EP
• Beacon devices for proximity sensing applications
• Configurable output power from -10dBm to +5dBm per application requirements
• Max. +8dBm output power with only 24mA current consumption, even in low-cost 8-pin SOP-EP package
• RF analog power supply
• Crystal oscillator input
• General-purpose pin
• No connect, leave floating
• PC clock input
• IC data pin
• RF digital power supply
• LDO output, connect to bypass capacitor
• No connect
• Exposed pad, connect to ground
• Supply voltage: VSS-0.3V~VSS+3.6V; Operating temperature: -40°C~85°C; I/O port voltage: VSS-0.3V~VDD+0.3V; ESD HBM: 2kV; Storage temperature: -60℃~150℃
• This IC is ESD sensitive. HBM (Human Body Mode) complies with MIL-STD-883
• Only rated power is emphasized here. Exceeding the absolute maximum ratings may damage the IC. Operation outside the specified ranges is undefined, and prolonged operation under such conditions may affect reliability
• Fully integrated 2.4GHz transmitter, comprising a fractional-N synthesizer, programmable PA, and power management module
• Synthesizer loop filter, 4.8GHz VCO, and DCXO are all integrated on-chip
• Transmission sessions use an enhanced direct VCO modulation architecture
• GFSK modulated signal is fed into the PLL via the fractional-N synthesizer
• A second signal path feeds directly into the VCO to compensate for PLL loop response
• Generates a GFSK signal with low FSK error
• Modulated signal is fed into the PA with maximum output power up to +8dBm
• Five operating modes: shutdown, deep sleep, light sleep, standby, and TX mode
• External MCU configures RF parameters, transfers data, and wakes up the RF IC via I2C interface
• Once the RFTXSTART control bit is enabled, I2C stops and the RF IC begins data transmission
• Deep sleep mode: crystal oscillator off. Light sleep mode: crystal oscillator on, RF frequency synthesizer off. Standby mode: crystal oscillator on, RF frequency synthesizer on, RF PA off. TX mode: crystal oscillator on, RF frequency synthesizer on, RF PA on. Idle mode: crystal oscillator off, LIRC on
• In light sleep mode, if both SDA and SCL pin states remain unchanged for 10ms, the IC transitions to deep sleep mode
• If the SDA or SCL pin state toggles and remains unchanged, the timer resets and restarts; the IC enters deep sleep mode after the 10ms count expires
• If a falling edge is detected on the SCL pin, the IC wakes from deep sleep mode; the low pulse width must be held for at least 1ms for the IC to return to light sleep state
• The host MCU can then control the IC via I2C protocol
• Each frame is transmitted continuously until the frame counter (PKT_AUTORS) stops and the IC enters light sleep mode
• PKT_APRD[4:0]: Auto-retransmit delay for packet format, 250us (Min.) ~8ms (Max.)
• PKT_AUTORS[7:0]: Auto-retransmit count for packet events
• 0: No retransmit (auto-retransmit disabled); 1: Retransmit once; 2: Retransmit twice; ... 254: Retransmit 254 times; 255: Continuous periodic retransmit until MCU forcibly disables TX
• During TX transmission, if the MCU clears the RFTXSTART bit, the TX transmitter stops after the current advertising event completes
• PKT_PERIODS[9:0]: Advertising event period; Period = 10ms × (1 + PKT_PERIODS[9:0]); 00-0000-0000: 10ms; 00-0000-0001: 20ms; 11-1111-1111: 10240ms (10.24s)
• HOP_FNO[2:0]: Number of hopping frequencies
• Bit0/Bit1/Bit2 represent enable bits for Ch37/Ch38/Ch39 respectively
• Setting all bits to "000" is not recommended. Ensure at least one channel is enabled
• Example: 001: Ch37 enabled, Ch38/Ch39 disabled — only Ch37 per advertising event; 110: Ch38/Ch39 enabled, Ch37 disabled — only Ch38 and Ch39 per advertising event; 101: Ch37/Ch39 enabled, Ch38 disabled — only Ch37 and Ch39 per advertising event; 111: Ch37/Ch38/Ch39 enabled — Ch37, Ch38, and Ch39 per advertising event
• I2C byte write, page write, byte read, and page read support
• For page write/read, the register address of the FIFO port (address: 10h) does not auto-increment during consecutive FIFO write/read operations
• Note: This I2C is a non-standard I2C interface; only one device can be connected
• Steps to write data to FIFO via I2C: Set RSTPDUFF bit to 1 to clear the FIFO pointer; RSTPDUFF automatically clears to 0 upon completion. Consecutively write data to address 10h; I2C remains at address 10h without auto-incrementing. Set the PDU data length to be transmitted via the PDULEN field. To reset PDU data, repeat steps 1–3
• CFG0: Configuration Register 0
• CFG7: Configuration Register 7
• CFGC: Configuration Register C
• CFGD: Configuration Register D
• CFG10: Configuration Register 10
• CFG11: Configuration Register 11
• CFG12: Configuration Register 12
• CFG15: Configuration Register 15
• CFG16: Configuration Register 16
• CFG17: Configuration Register 17
• CFG18: Configuration Register 18
• CFG1A: Configuration Register 1A
• CFG1D: Configuration Register 1D
• CFG1E: Configuration Register 1E
• CFG25: Configuration Register 25
• CFG26: Configuration Register 26
• CFG27: Configuration Register 27
• CFG2A: Configuration Register 2A
• CFG30: Configuration Register 30
• CFG31: Configuration Register 31
• CFG33: Configuration Register 33
• Package information (outline dimensions, carrier tape, and reel specifications)
• Package material information
• Carton information
• 8-pin SOP-EP [50mil] outline dimensions
• 10-pin MSOP-EP (118mil) outline dimensions

• Indoor navigation
• Healthcare
• Beacon devices for proximity sensing applications