AK2364 Datasheet, PDF (20/26 Pages) Asahi Kasei Microsystems – Two-way Radio Filterless FM Detector LSI

[AK2364]
2) AVDD=3.6 to 5.5V operation
When you use AK2364 in AVDD=3.6 to 5.5V operation, please set LDO power on setting.
Refer to 4-2) in page 23.
Following procedure is required before calibration in LDO power on setting.
<1> Start up the external TCXO and continuously supply LO signal to AK2364.
<2> Set “10” to 0x01 {BS[1:0]} and start up VIREF circuits. This makes LDO set power up standby.
<3> Set “0” to 0x01 {LDOSTAT} and LDO output shortened VSS once. This makes LDO power up
time shortly.
<4> Set “1” to 0x01 {LDOSTAT} and “1” to 0x01 {PDLDON}, then LDO power is on. It takes 130ms
for AGNDIN pin output voltage to become stable.
<5> Set “11” to 0x01 {BS[1:0]} and start up all circuits. After this operation, the circuits necessary for
calibration (LOBUF,VIREF and Discriminator) will be powered on and calibration can be
possible in 500us.
<6> Calibration is begun by setting "1" to address 0x02 {CAL}. When the calibration is executed
once, the calibration operation cannot be stopped excluding master reset. Even if "0" is written
in {CAL}, the calibration is completely executed.
<7> Calibration data is maintained excluding the time when the master reset is executed or DVDD
power supply is down.
<8> It takes 1.5ms for Discriminator to become stable after the calibration is completed.
Power-up sequence recommendation
LOIN（External） ^Unstable
{BS[1:0]}
{LDOSTAT}
{PDLDON}
AGNDIN
LOBUF
VIREF
Discriminator
{CAL}
“01”
“10”
(100μs) (50μs)
(130ms)
Unstable
(500μs)
Unstable
Reset itself automatically after calibration is completed
Internal Discriminator
“11”
Stable
(1.3ms)
Stable
(1.5ms)
Unstable
Note: These values refer to the following recommended external application circuits.
MS1431-E-01
- 20 -
2012/10