LA17000M
No. 6522-25/54
CTC data: This is the input sensitivity switch data; when CTC = 1, the input sensitivity is degraded.
HCTR: Minimum input sensitivity standard f [MHz]
CTC
0.4
≤ f < 8
8
≤ f < 12
12
≤ f < 25
0 (Normal mode)
40 mVrms
(1 to 10 mVrms)
1 (Degraded mode)
—
70 mVrms
—
(30 to 40 mVrms)
—: Not stipulated (operation not guaranteed)
( ): Actual performance estimates (reference value)
CTP data: This is data that determines the status of the general-purpose counter input pin (HCTR/LCTR) when a
general-purpose counter reset (CTE = 0) is executed.
CTP = 0: Pulls down the general-purpose counter input pin.
= 1: Does not pull down the general-purpose counter input pin, reducing the wait time to 1 or 2 ms.
When setting CTP = 1, do so at least 4 ms prior to starting the count (CTE = 1). If the counter is not to be
used, set CTP = 0.
IF Counter Operation
Before starting counting with the general-purpose counter, the general-purpose counter must first be reset by setting CTE
= 0. The general-purpose counter is made to start counting by setting serial data CTE = 1. The serial data is finalized
within the PLL by changing CE from high to low, but input to the HCTR pin must be started within the wait period after
CE is sent low at the very latest. After measurement ends, the count results from the general-purpose counter must be
read while CTE = 1. (Once CTE is set to zero, the general-purpose counter is reset.) Furthermore, the signal that was
input to the HCTR pin is passed through to the general-purpose counter after having been divided by 1/2 internally.
Therefore, the general-purpose count results are actually 1/2 the actual frequency of the signal that was input to the
HCTR pin.
Frequency measurement mode
Cycle
GT1
GT0
Measurement
Wait time
measurement
time
CTP = 0
CTP = 1
mode
0
4 ms
3 to 4 ms
1 cycle
01
8
1 to 2 ms
10
32
7 to 8 ms
2 cycles
11
64
40 mVrms or more*
(when measuring frequency)
* CTC = 0: 40 mVrms
CTC = 1: 70 mVrms
Signal input
Measurement
time
Wait time
Frequency measurement time
CTE = 1
data