ZSLS7025ZI1R ZMDI, ZSLS7025ZI1R Datasheet - Page 17

• Manufacturer Part Number: ZSLS7025ZI1R
• Description: LED Lighting Drivers LED Driver
• Manufacturer: ZMDI

Specifications of ZSLS7025ZI1R

• Rohs: yes
• Input Voltage: 5 V
• Maximum Supply Current: 400 uA
• Maximum Operating Temperature: + 125 C
• Mounting Style: SMD/SMT
• Package / Case: SOIC-8
• Minimum Operating Temperature: - 40 C

3
3.1
The under-voltage lockout (UVLO) function monitors the voltage on the ZSLS7025’s VDD pin. If this voltage is
lower than the UVLO threshold minus the UVLO hysteresis (V
If the voltage on the VDD pin reaches a level higher than the UVLO threshold (V
turns off and the ZSLS7025 is re-enabled. See parameters 1.3.2 and 1.3.3 in section 1.3 for the V
threshold and V
3.2
Open-load protection is achieved through the ZSLS7025's over-voltage protection (OVP). In boost converters, an
LED string failure can cause the feedback voltage (V
keep boosting the output voltage higher and higher. If the output voltage reaches the programmed OVP threshold,
the protection mechanism will be triggered and stop the switching action. To ensure that the circuit functions
properly, the OVP setting resistor divider, R
The recommended OVP voltage is either 1.25 times the normal output voltage or 5V higher than the normal
output voltage, whichever is higher.
Where
Data Sheet
June 28, 2012
ZSLS7025
Boost LED Driver
V
V
OVP_TH
OVP
Operating Conditions
Under-Voltage Lockout
Over-Voltage Protection
= Output voltage OVP level
V
OVP
= Over-voltage input threshold: 1.0V (typical; see parameter 1.3.12 in section 1.3)
UVLO_HYS

V
© 2012 Zentrum Mikroelektronik Dresden AG — Rev.1.00
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is subject to changes without notice.
OVP
_
hysteresis, respectively.
TH

(
R
1
R

2
R
2
)
1
and R
2
, must be set with appropriate values given by equation (13).
FB
) to always be zero. If this happens, the ZSLS7025 will
UVLO_TH
- V
UVLO_HYS
), the ZSLS7025 is disabled.
UVLO_TH
), the lock-out function
(13)
17 of 27
UVLO_TH