Specifications
. 
OG_STD-302N-R_v15e  Circuit Design, Inc. 
10
OPERATION GUIDE
PLL IC CONTROL 
  PLL IC control  
OSCin
OSCout
Vp
VCC
Do
GND
Xf in
Fin
R
P
STD-302
Control pin name
ZC
PS
LE
Data
2kohm
MB15E03SL
Reference Oscillator
LPF
Voltage Controled
Oscillator
VCO
PLL
CLK
DATA
LE
LD
LD/f out
+2.8v
#:Control v oltage = +2.8v
21.25MHz
up to 1200MHz
Figure 1
CLK
2kohm
2kohm
2kohm
STD-302N-R is equipped with an internal PLL frequency synthesizer as shown in Figure 1. The operation of 
the PLL circuit enables the VCO to oscillate at a stable frequency. Transmission frequency is set externally by 
the controlling IC. STD-302N-R has control terminals (CLK, LE, DATA) for the PLL IC and the setting data is 
sent to the internal register serially via the data line. Also STD-302N-R has a Lock Detect (LD) terminal that 
shows the lock status of the frequency. These signal lines are connected directly to the PLL IC through a 2 kΩ 
resistor. 
The interface voltage of STD-302N-R is 2.8 V, so the control voltage must be the same. 
STD-302N-R comes equipped with a Fujitsu MB15E03SL PLL IC. Please refer to the manual of the PLL IC. 
The following is a supplementary description related to operation with STD-302N-R. In this description, the 
same names and terminology as in the PLL IC manual are used, so please read the manual beforehand. 










