Datasheet

Datasheet

3/36

TSZ02201-0T3T0C600070-1-2

© 2016 ROHM Co., Ltd. All rights reserved.

2016.10.19 Rev.003

www.rohm.com

BD81A24MUV-M/EFV-M

TSZ22111・15・001

Description of Blocks

1. Voltage Reference (VREG)

internal circuit and when fixing the pins outside of the IC at a high voltage, as well. The UVLO protection is integrated in

VREG≤2.0V (Typ). For release/cancellation condition and detection condition, please refer to Table 2 on page 11. Connect a

ceramic capacitor (CREG) to VREG terminal for phase compensation. CREG range is 1.0µF to 4.7µF and recommend value

is 2.2µF. If the CREG is not connected, the operation of circuit will be notably unstable.

2. Constant Current Driver

Table1. LED Control Logic

LEDEN1

LEDEN2

LED1

LED2

LED3

LED4

L

L

ON

ON

ON

ON

H

L

ON

ON

ON

OFF

L

H

ON

ON

OFF

OFF

H

H

ON

OFF

OFF

OFF

If less than four constant-current drivers are used, please make the LED1 to 4 terminal ‘open’ while the output ‘OFF’ by

LEDEN1 and LEDEN2 terminal. The truth table for these pins is shown above. If the unused constant-current driver output

will be set open without the process of LEDEN1,2 terminals, the ‘open detection’ will be activated. The LEDEN1, 2 terminals

is pulled down internally in the IC and it is low at ‘open’ condition. They should be connected to VREG terminal or fixed to

logic HIGH when in use.

Figure 4. ILED vs RISET

The Output Current ILED can be obtained by the following equation:

[

] = (1.0

[ Ω]

⁄

) × 5000

RISET operating range is 41kohm to 250kohm. It cannot change the RISET value in the operation.

This IC has ISET-GND short protection that protect LED element from over current when ISET and GND is short. If the

RISET value is under 4.7kohm, the IC detects ISET-GND short and LED current becomes off.

20

30

40

50

60

70

80

90

100

110

120

40

60

80

100 120 140 160 180 200 220 240

RISET[kΩ

]

ILED vs RISET