Transimpedance converter of signals of avalanche photodetectors and silicon photomultipliers

FIELD: radio engineering, communication.

SUBSTANCE: transimpedance converter of signals of avalanche photodetectors and silicon photomultipliers comprises a current signal source (1), connected to the current input of the device (2) and the emitter of an input transistor (3), a current-stabilising two-terminal element (4), connected between the emitter of the input transistor (3) and the first (5) power supply bus, a first (6) auxiliary voltage source, connected to the base of the input transistor (3), a second (7) auxiliary voltage source, connected to the base of an output transistor (8), the emitter of which is connected to the collector of the input transistor (3), a collector load two-terminal element (9), connected between the collector of the output transistor (8) and a second (10) power supply bus, a buffer amplifier (11), the input of which is connected to the collector of the output transistor (8), and the output is the output of the device (12). The output of the device (12) is connected to the emitter of the output transistor 8 through a balancing capacitor (13).

EFFECT: wider operating frequency range.

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The present invention relates to the field of radio and communication and can be used in processing systems optical data, sensors, optical radiation of low intensity, a measure of optical signals in high energy physics, etc.

Optical radiation (AOI) includes the spectra of ultraviolet, visible and infrared ranges. It can register different types of sensors, among which the most frequently used photodiodes and silicon photomultipliers, reacting, as a rule, for a certain range of radiation. The reporting unit refers to such types of signal converters.

In the tasks of separating optical signals are now widely used converters currents of avalanche photodiodes and silicon photomultipliers based on cascades with low input resistance - transimpedance amplifiers (schemes with a common base, kaskadnykh amplifiers, etc.) [1-10]. To reduce the noise level of such transducers are used in parallel 10-50 elementary transistors [11], form input kaskadou structure. However, this build circuits significantly narrows the range of operating frequencies, due mainly to the equivalent parasitic capacitances of a large number (10-50) parallel coupled transistors and the tanks on the substrate and containers collector-base. In this regard, it is highly important task of building signal transducers avalanche photodiodes and silicon photomultipliers, which have a wider operating frequency range while maintaining a small level of noise caused by the input transistors.

The closest prototype of the proposed device is the signal Converter of avalanche photodiodes and silicon photomultipliers, are presented in the monograph "Elemental basis of radiation-resistant information-measuring systems / PEM, Oviformis, Sguschenki; under the General editorship of Professor Dr. Pop - Mine: FGBOU VPO "law", 2011. - S, (figure 1.12)". It contains the current source 1 is connected to the current input device 2 and the emitter of the input transistor 3, dakotabilities dvukhpolosnykh 4 connected between the emitter of the input transistor 3 and the first 5 bus power supply, the source of the first 6 auxiliary voltage connected to the base input of the transistor 3, the second source 7 auxiliary voltage connected to the base of the output transistor 8, the emitter of which is connected to the collector of the input transistor 3, dvukhpolosnykh collector load 9 connected between the collector of the output transistor 8 and second 10-bus power supply, the buffer amplifier 11, an input connected to the call is ktoroy the output of the transistor 8, and the output is the output device 12.

A significant disadvantage of the known transimpedance signal transducer avalanche photodiodes and silicon photomultipliers of the prototype is that it does not have a sufficiently wide frequency range, which limits its use in high-speed detectors of optical radiation.

The main objective of the present invention is to increase the operating frequency range, which is determined by the upper boundary frequency f_indevice (at-3dB level).

The problem is solved in that the signal Converter of avalanche photodiodes and silicon photomultipliers figure 1, containing the current source 1 is connected to the current input device 2 and the emitter of the input transistor 3, dakotabilities dvukhpolosnykh 4 connected between the emitter of the input transistor 3 and the first 5 bus power supply, the source of the first 6 auxiliary voltage connected to the base input of the transistor 3, the second source 7 auxiliary voltage connected to the base of the output transistor 8, the emitter of which is connected to the collector of the input transistor 3, dvukhpolosnykh collector load 9 connected between the collector of the output transistor 8 and second 10 bus power supply, the buffer amplifier 11, the input to the th is connected to the collector of the output transistor 8, and the output is an output device 12, there are new elements and connections of the output device 12 is connected to the emitter of the output transistor 8 through the adjustment capacitor 13.

Figure 1 shows the input cascade commercially available chip Ampl 1-18 [11].

Figure 2 presents a functional diagram transimpedance transducer signals (TPS) avalanche photodiodes and silicon photomultipliers, the corresponding figure 1.

Figure 3 shows the proposed scheme transimpedance signal transducer avalanche photodiodes and silicon photomultipliers.

Figure 4 shows the equivalent circuit of the input stage transimpedance signal transducer avalanche photodiodes and silicon photomultipliers in the environment PSpice models of integrated transistors "ABMC" (Transistors: npn GC1E, pnp JFpnp, abmk l.4 (JSC MNPI").

Figure 5 presents LATCH input stage figure 4 for different values of capacitance adjustment capacitor C1=C13.

Transimpedance the signal Converter of avalanche photodiodes and silicon photomultipliers contains the current source 1 is connected to the current input device 2 and the emitter of the input transistor 3, dakotabilities dvukhpolosnykh 4 connected between the emitter of the input transistor 3 and the first 5 bus power supply, the source of the first 6 auxiliary materials is inogo voltage, connected to the base input of the transistor 3, the second source 7 auxiliary voltage connected to the base of the output transistor 8, the emitter of which is connected to the collector of the input transistor 3, dvukhpolosnykh collector load 9 connected between the collector of the output transistor 8 and second 10-bus power supply, the buffer amplifier 11, whose input is connected to the collector of the output transistor 8, and the output is the output device 12. The output device 12 is connected to the emitter of the output transistor 8 through the adjustment capacitor 13.

Consider the circuit transimpedance signal transducer prototype 2.

The time constant τ_indefining the upper boundary frequency of the conversion factor R(jω) input current (i_Iin the output voltage U_o=U₁₂, determined by the formula:

$$t_{\mathrm{in}\Sigma }\approx R_9\left(C_{14}+C_{15}\right)\left(2\right)$$

where C₁₄With₁₅- parasitic capacitance to the substrate (C₁₄) and capacitance collector-base (C₁₅) m=10÷50 parallel to the elementary transistors in the structure of the output transistor 8.

As a consequence, the upper cutoff frequency of the TPN in figure 2 the equation of its frequency dependence R(jω) (1) is determined by the expression

$$f_{\mathrm{in}}=\frac{1}{2\pi t_{\mathrm{in}\Sigma }}\left(3\right)$$

Due to the fact that the number of elementary transistors in item 8, define f_inthe device is high enough, the range of operating frequencies TPS 2 is small.

$$C_{ef.\Sigma }\approx \left(C_{14}+C_{15}\right)\left(1-{\alpha }_8{K}_{y11}\right)\left(4\right)$$

where K_u≈ 1 - gain voltage buffer amplifier 11.

As a consequence, the upper cutoff frequency of TPS 3

$$f_{\mathrm{in}}^{*}=\frac{1}{R_9\left(C_{14}+C_{15}\right)\left(1-{\alpha }_8{K}_{y11}\right)}\left(5\right)$$

In igris $$f_{\mathrm{in}}^{*}$$compared with f_inscheme 2 reaches values

$$N_{\mathrm{in}}=\frac{f_{\mathrm{in}}^{*}}{f_{\mathrm{in}}}\approx \frac{1}{1-{\alpha }_8{K}_{y11}}\ge 1\left(6\right)$$

where f_inthe upper cutoff frequency of the SCC prototype 2 is defined by the formula (3).

The results of circuit simulation figure 3 confirm the effect of increasing the upper frequency limit of the claimed TPS - introduction of new elements and relationships between them extends the operating frequency range transimpedance Converter 3 7-10 times.

Thus, the proposed circuit decision transimpedance signal transducer avalanche photodiodes and silicon photomultipliers characterized by higher performance.

BIBLIOGRAPHIC LIST

1. Patent US 6.590.455fig.1.

2. Patent US 6.069.534 fig.6.

3. Patent US 6.801.084.

4. Patent US 6.218.905.

5. Patent US 6.639.477 fig.3.

6. Patent US 6.809.594 fig.1.

7. Patent US 5.714.909 fig.2.

8. Patent US 7.042.295.

9. Patent US 4.511.857 fig.3.

10. P the tent US 5.345.073 fig.3.

11. Element base radiation-resistant information-measuring systems: monograph / Pop, Oviformis, Sguschenki; under the General editorship of Professor Dr. PoE;

FGBOU VPO "the South Grew. state Univ tons of Economics and service". - Mine:

FGBOU VPO "law", 2011. - S, (figure 1.12).

Transimpedance the signal Converter of avalanche photodiodes and silicon photomultipliers containing the current signal source (1)connected to the current input device (2) and the emitter of the input transistor (3), dakotabilities dvukhpolosnykh (4)connected between the emitter of the input transistor (3) and the first (5) bus power supply, the source of the first (6) auxiliary voltage connected to the base input of the transistor (3), the source of the second (7) auxiliary voltage connected to the base of the output transistor (8), the emitter of which is connected to the collector of the input transistor (3)dvukhpolosnykh collector load (9)connected between the collector of the output transistor (8) and second (10) bus power supply, the buffer amplifier (11), the inlet of which is connected to the collector of the output transistor (8), and the output is the output device (12), characterized in that the output unit (12) is connected to the emitter of the output transistor 8 through the adjustment capacitor (13).