Model 18C and Model 19C

Features High Input Impedance Low Input Capacitance DC to 350 MHz Can be mounted on any micropositioner with any probing system
	FIGURE 1

High impedance probes, PICOPROBE® MODEL 18C and MODEL 19C, combine the most advanced MOS and bipolar technologies with special, low capacitance packaging techniques to achieve truly remarkable electronic measurement capabilities. While being manufactured each instrument is individually optimized for the best possible performance. The extremely low input capacitance, high input impedance, and almost negligible input leakage current permits the direct probing of even the most sensitive MOS dynamic nodes. At the same time, the full dc capability of this Picoprobe coupled with the high speed capability permits the full characterization of circuits.

The 10 micron tungsten probe wire is tapered to an extremely fine point to allow probing of the finest lines. The fine probe wire flexes when in contact with the circuit, so that damage to the circuit and probe point is minimized. Also the flexing tends to keep the probe point in contact with the circuit even in the presence of probe table vibrations. Model 18C and Model 19C probe tips are also available with a 20 and 50 micron tungsten probe wire sharpened to less than 1 and 3 microns respectively.

The circuitry located in the Model 18C and Model19C Picoprobe® body is very rugged; however, the unprotected MOS input in each probe tip is subject to destruction by electrostatic discharge. Should the probe tip become damaged, it can easily be removed and replaced.

Specifications	Model 18C	Model 19C
Input Capacitance*	0.02pF	0.02pF
Input Leakage	10 femtoamps	10 femtoamps
Rise/Fall Time	1.2ns	1.2ns
Frequency Response	dc to 350 MHz	dc to 350 MHz
Operating Range	0 to + 10V range **	-7 to + 3V***
Linearity	0.2% 5V range / 2.0% 10V range	0.2% ± 3V range / 2.0% -7 to +3V range
Gain Accuracy	±5%	±5%
Signal Attenuation	(High input impedance oscilloscope) 10 to 1 (50 ohm input) 20 to 1	(High input impedance oscilloscope) 10 to 1 (50ohm input) 20 to 1
*For 3ns or longer rise and fall signals. Speed limitations of the capacitance cancelling circuitry results in approximately 0.06pF input capacitance for 1ns or shorter rise or fall inputs. ** For 0V to +15V please see the higher voltage part number in the table below. ***For -7V to +8V please use the higher voltage part number in the table below.
Requires the use of a Picoprobe Power Supply. Please specify 110V or 220V when ordering.
FIGURE 2

 

Picoprobe® Model 18C and Model 19C Replacement Tips*
Standard Part Number	Higher Voltage Part Number	Tungsten Wire Shaft Diameter	Point Radius
18C-1-5	18C-1-5-HV	5 micron	<0.1 micron
18C-1-10	18C-1-10-HV	10 micron	<0.1 micron
18C-1-20	18C-1-20-HV	20 micron	<1.0 micron
18C-1-50	18C-1-50-HV	50 micron	<3.0 micron
18C-2-5	18C-2-5-HV	5 micron	<0.1 micron
18C-2-10	18C-2-10-HV	10 micron	<0.1 micron
18C-2-20	18C-2-20-HV	20 micron	<1.0 micron
18C-2-50	18C-2-50-HV	50 micron	<3.0 micron
18C-4-5	18C-4-5-HV	5 micron	<0.1 micron
18C-4-10	18C-4-10-HV	10 micron	<0.1 micron
18C-4-20	18C-4-20-HV	20 micron	<1.0 micron
18C-4-50	18C-4-50-HV	50 micron	<3.0 micron

FIGURE 3

photos not to scale

Model 18C Pdf