BU2618FV
BU2618FV is PLL frequency synthesizer for tuners manufactured by ROHM.
Audio ICs
PLL frequency synthesizer for tuners
The BU2618FV is a low current dissipation PLL frequency synthesizer designed for use in FM multiplex radio receiver and FM pager receiver. Featuring very small package and built-in prescaler that can operate at up to 130MHz.
FApplications FM multiplex radio receivers, pagers, radios, and other signal generators
FFeatures 1) Built-in high-speed prescaler can divide 130 MHz VCO. 2) Low current dissipation (during operation: 1.5m A, PLL OFF: 200µA Typ.) 3) Seven standard frequencies: 25k Hz, 12.5k Hz, 6.25k Hz, 10k Hz, 9k Hz, 5k Hz, and 1k Hz.
4) 5) 6) 7)
Counter for intermediate frequency detection. Unlock detection circuit. Four output ports. Serial data input (CE, CK, DA)
FAbsolute maximum ratings (Ta = 25_C)
FRemended operating conditions (Ta = 25_C)
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FBlock diagram
FPin descriptions
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FElectrical characteristics (unless otherwise noted, Ta = 25_C, VDD = 3.0V)
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FCircuit operation
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S Explanation of the data (1) Division data: For D0 through D15 (When S = 0, use D4 through D15.)
(2)
(3)
(4)
CT: Frequency measurement beginning data 1: Begins measurement. 0: Resets internal counter, IFIN goes to pulldown. Output port control data: 1: Open drain output ON 2: Open drain output OFF R0, R1, R2, standard frequency data
(5) (6) (7)
S: switch between FMIN and AMIN 0: FMIN 1: AMIN PS: If this bit is set to ON while AMIN is selected, swallow counter division is possible. GT: Frequency measurement time and unlock detection ON / OFF
(8)
TS: Test data
(0) is input
Audio ICs
S Frequency counter (1) Structure
(2)
How the frequency counter operates When control data CT equals 1, the 20-bit counter and the amp go into operation. When CT equals 0, amp input goes to pulldown and the counter is reset. Measuring time (gate pulse) is selected (16ms / 32ms) on the basis of control data GT. When control data CT...
