CP3BT26G18NEPX/NOPB National Semiconductor, CP3BT26G18NEPX/NOPB Datasheet - Page 78

• Manufacturer Part Number: CP3BT26G18NEPX/NOPB
• Manufacturer: National Semiconductor

Specifications of CP3BT26G18NEPX/NOPB

• Operating Temperature (min): -40C
• Operating Temperature (max): 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 128
• Package Type: LQFP
• Lead Free Status / RoHS Status: Compliant

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15.3
To power-up a Bluetooth system based on the CP3BT26
and LMX5251 devices, the following sequence must be per-
formed:
1. Apply VDD to the LMX5251.
2. Apply IOVCC and VCC to the CP3BT26.
3. Drive the RESET# pin of the LMX5251 high a minimum
4. After internal Power-On Reset (POR) of the CP3BT26,
5. When the RFDATA pin is driven high, the LMX5251 en-
6. The Bluetooth baseband processor on the CP3BT26
7. In “normal” mode, the oscillator of the LMX5251 is con-
of 2 ms after the LMX5251 and CP3000 supply rails are
powered up. This resets the LMX5251 and CP3BT26.
the RFDATA pin is driven high. The RFCE, RFSYNC,
and SDAT pins are in TRI-STATE mode. Internal pull-
up/pull-down resistors on the CCB_CLOCK (SCLK),
CCB_DATA
TX_RX_SYNC (RFSYNC) inputs of the LMX5251 pull
these signals to states required during the power-up
sequence.
ables its oscillator. After an oscillator start-up delay, the
LMX5251 drives a stable 12-MHz BBP_CLOCK
(BBCLK) to the CP3BT26.
now directly controls the RF interface pins and drives
the logic levels required during the power-up phase.
When the RFCE pin is driven high, the LMX5251
switches from “power-up” to “normal” mode and dis-
ables the internal pull-up/pull-down resistors on its RF
interface inputs.
trolled by the RFCE signal. Driving RFCE high enables
the oscillator, and the LMX5251 drives its BBP_CLOCK
(BBCLK) output.
Figure 23. LMX5251 Power-Up Sequence
LMX5251 POWER-UP SEQUENCE
(SDAT),
CCB_LATCH
(SLE),
and
78
15.4
A Bluetooth system based on the CP3BT26 and LMX5252
devices has the following states:
! Off—When the LMX5252 enters Off mode, all configura-
! Power-Up—When the power supply is on and the
! RF Init—The baseband controller on the CP3BT26 now
! Idle—The baseband controller on the CP3BT26 drives
! Sleep—The LMX5252 can be forced into Sleep mode at
! Wait XTL—When RFCE goes high, the crystal oscillator
The power-up sequence for a Bluetooth system based on
the CP3BT26 and LMX5252 devices is shown in Figure 25.
tion data is lost. In this state, the LMX5252 drives BPOR
low.
LMX5252 RESET# input is high, the LMX5252 starts up
its crystal oscillator and enters Power-Up mode. After the
crystal oscillator is settled, the LMX5252 sends four
clock cycles on BRCLK (BBCLK) before driving BPOR
high.
drives RFCE high and takes control of the crystal oscilla-
tor. The baseband performs all the needed initialization
(such as writing the registers in the LMX5252 and crystal
oscillator trim).
RFDATA low when the initialization is ready. The
LMX5252 is now ready to start transmitting, receiving, or
enter Sleep mode.
any time by driving RFCE low. All configuration settings
are kept, only the Bluetooth low power clock is running
(B3k2).
becomes operational. When it is stable, the LMX5252
enters Idle mode and drives BRCLK (BBCLK).
LMX5252 POWER-UP SEQUENCE
Figure 24. LMX5252 Power States