LH0033CG Ver la hoja de datos (PDF) - Calogic, LLC

Número de pieza

componentes Descripción

Fabricante

LH0033CG

Fast Buffer

Calogic, LLC 

LH0033 / LH0033C

CORPORATION

Figure 3. In Figure 3, the current sources are saturated

during normal operation, thus apply full supply voltage to the

VC pins. Under fault conditions, the voltage decreases as

required by the overload.

For Figure 5:

RLIM

=

VBE

ISC

=

0.6V

60mA

=

10Ω

Capacitive Loading

The LH0033 is designed to drive capacitive loads such as

coaxial cables in excess of several thousand picofarads

without susceptibility to oscillation. However, peak current

resulting from (C × dV/dt) should be limited below absolute

maximum peak current ratings for the devices.

Thus for the LH0033:

(

∆VIN

∆t

)

×

CL

≤

IOUT

≤

±250mA

In addition, power dissipation resulting from driving capacitive

loads plus standby power should be kept below total package

power rating:

PDpkg. ≥ PDC + PAC

PDpkg. ≥ (V+–V–) × IS + PAC

PAC ≅ (Vp-p)2 × f × CL

where:

Vp-p = Peak-to-peak output voltage swing

f = Frequency

CL = Load Capacitance

Operation Within An Op Amp Loop

LH0033 may be used as a current booster or isolator buffer

within a closed loop with op amps such as LH0032, or

CLM4124. An isolation resistor of 47Ω should be used between

the op amp output and the input of LH0033. The wide bandwidth

and high slew rate of the LH0033 assure that the loop has the

characteristics of the op amp and that additional rolloff is not

required.

Hardware

In order to utilize the full drive capabilities of LH0033, it should

be mounted with a heat sink particulary for extended

temperature operation. The case is isolated from the circuit

and may be connected to the system chassis.

Design Precaution

Power supply bypassing is necessary to prevent oscillation.

Low inductance ceramic disc capacitors with the shortest

practical lead lengths must be connected from each supply

lead (within <1⁄4" to 1⁄2" of the device package) to a ground

plane. Capacitors should be one or two 0.1µF in parallel;

adding a 4.7µF solid tantalum capacitor will help troublsome

instances.

FIGURE 3. Current Limiting Using Current Sources

+15V

INPUT

R LIM

10

Q2

12

Q1

5

LH0033

1

11

9

10

7

6

30k

OUTPUT

0.01µF

Q1 = Q2 = 2N2905

Q3 = Q4 = 2N2219

Q3

Q4

R LIM

10

-15V

CALOGIC CORPORATION, 237 Whitney Place, Fremont, California 94539, Telephone: 510-656-2900, FAX: 510-651-1076

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