TTL Freq. Divider (f/2, f/10)


$ 695.75


  • 100 MHz Toggle Frequency
  • 50 Ω Outputs deliver > 2.2 V into 50 Ω loads
  • TTL/CMOS Compatible Input Levels
  • 50 Ω or 500 Ω Input Resistance
  • BNC I/O Connectors
  • Ready-to-Use 1.3 x 2.9 x 2.9-in. Module includes AC/DC Adapter


  • Count down signal for 'scope trigger
  • Control Signal for split cycle timing
  • Counter Output simulation Square Wave Generator
  • An Essential Lab Tool for Working with TTL/CMOS Circuits
  • Download Datasheet


The PRL-240A is a self-contained high-speed TTL frequency divider capable of operating at clock frequencies in excess of 100 MHz. The PRL-240A has ÷2 and ÷10 outputs. The input resistance can be set to 500 Ω or 50 Ω by a toggle switch. A functional block diagram is shown in Fig.1.

The back-matched 50 Ω outputs can drive long lines and deliver greater than 2.2 V into 50 Ω loads.

The ÷2 output is a square wave, and the ÷10 output has an output pulse positive duty cycle of 40%. The square wave is useful for testing High and Low pass filters. The divider outputs are useful as 'scope triggers for viewing multi-frequency signals. The ÷2 signal is often needed as a control signal for split-cycle timing applications.

Each unit is housed in an attractive 1.3 x 2.9 x 2.9-in. extruded aluminum enclosure and has BNC I/O connectors. A ±8.5 V AC/DC Adapter is supplied with each unit.


At power-up all internal counters are in the default state, and the outputs are all low. All output state changes occur on the rising edges of fIN.

  • f/2 Output:
    • 1st rising edge on the 1st rising edge of fIN.
    • 1st falling edge on the 2nd rising edge of fIN.
    • 2nd rising edge on the 3rd rising edge of fIN.
    • 2nd falling edge on the 4th rising edge of fIN.
  • f/10 Output:
    • 1st rising edge on the 4th rising edge of fIN.
    • 1st falling edge on the 8th rising edge of fIN.
    • 2nd rising edge on the 14th rising edge of fIN.
    • 2nd falling edge on the 18th rising edge of fIN.

(0° C ≤ TA ≤ 35° C)*

Symbol Parameter Min Typ Max Unit Comments
RIN (Lo) Input Resistance 49.5 50.0 50.5 Ω
RIN (Hi) Input Resistance 495 500 505 Ω
IDC DC Input Current 135 180 mA
VDC DC Input Voltage 7.5 8.5 12.0 V
VAC1 AC/DC Adapter Input Voltage, 120 VAC 103 115 127 V
VAC2 AC/DC Adapter Input Voltage, 220 VAC 206 230 254 V
VIH Input Hi Level 2.0 2.5 5.0 V
VIL Input Lo Level -0.5 0.0 0.5 V
VOH1 Output Hi Level, RLOAD = 50 Ω 2.2 2.5 V
VOH2 Output Hi Level, RLOAD = 1 MΩ 4.8 5.0 V
VOL1 Output Lo Level , RLOAD = 50 Ω 0.15 0.25 V
VOL2 Output Lo Level, RLOAD = 1 MΩ 0.30 0.50 V
TPLH Propagation Delay to f/n↑ output 10 13 ns
TPHL Propagation Delay to f/n↓ output 10 13 ns
tr Rise Time (10%-90%) 2.0 3.0 ns
tf Fall Time (10%-90%) 1.8 3.0
TSKEW Skew between outputs 1 2 ns
FMAX Max clock frequency 100 MHz
Size 1.3 x 2.9 x 2.9 in.
Shipping weight, incl. AC adapter 4 lb.
*All AC measurements are made with all outputs terminated into 50 Ω