3

Plastic Optical Fiber (1 mm POF) Transmitter Application Circuit

Performance of the HFBR-1527ETZ transmitter in the recommended application circuit (Figure 1) for POF; 1-125 MBd, 25° C.

Parameter

Symbol

Typical

Unit

Condition

Note

Average Optical Power 1 mm POF

-9.7

dBm

50% Duty Cycle

Note 1, Fig 3

Average Modulated Power 1 mm POF

-11.3

dBm

Note 2, Fig 3

Optical Rise Time (10% to 90%)

2.1

ns

5 MHz

Optical Fall Time (90% to 10%)

2.8

ns

5 MHz

High Level LED Current (On)

19

mA

Note 3

Low Level LED Current (Off )

3

mA

Note 3

Optical Overshoot – 1 mm POF

45

%

Transmitter Application Circuit Current Consumption –

1 mm POF

110

mA

Figure 1

Hard Clad Silica Fiber (200 μm HCS) Transmitter Application Circuit

Performance of the HFBR-1527ETZ transmitter in the recommended application circuit (Figure 1) for HCS; 1-125 MBd,

25° C.

Parameter

Symbol

Typical

Unit

Condition

Note

Average Optical Power 200 μm HCS

-14.6

dBm

50% Duty Cycle

Note 1, Fig 3

Average Modulated Power 200 μm HCS

-16.2

dBm

Note 2, Fig 3

Optical Rise Time (10% to 90%)

3.1

ns

5 MHz

Optical Fall Time (90% to 10%)

3.4

ns

5 MHz

High Level LED Current (On)

60

mA

Note 3

Low Level LED Current (Off )

6

mA

Note 3

Optical Overshoot – 200

m HCS

30

%

Transmitter Application Circuit Current Consumption –

200

m HCS

130

mA

Figure 1

Notes:

1. Average optical power is measured with an average power meter at 50% duty cycle, after 1 m of fiber.

2. To allow the LED to switch at high speeds, the recommended drive circuit modulates LED light output between two non-zero power levels. The

modulated (useful) power is the difference between the high and low level of light output power (transmitted) or input power (received), which

can be measured with an average power meter as a function of duty cycle (see Figure 3). Average Modulated Power is defined as one half the slope

of the average power versus duty cycle:

Average Modulated Power =

(2) [0.80 – 0.20]

3. High and low level LED currents refer to the current through the HFBR-1527ETZ LED. The low level LED “off” current, sometimes referred to as

“hold-on” current, is prebias supplied to the LED during the off state to facilitate fast switching speeds.