ZLED7015ZI1R ZMDI, ZLED7015ZI1R Datasheet - Page 18

• Manufacturer Part Number: ZLED7015ZI1R
• Description: LED Lighting Drivers LED driver
• Manufacturer: ZMDI

Specifications of ZLED7015ZI1R

• Rohs: yes
• Input Voltage: 6 V to 30 V
• Maximum Supply Current: 2 mA
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Package / Case: MSOP-10
• Minimum Operating Temperature: - 40 C

4
4.1
The under-voltage lockout (UVLO) monitors the ZLED7015’s internal regulator output voltage, VP, to ensure
correct operation of the internal circuitry. When the VP voltage is lower than the UVLO threshold V
ZLED7015 disables the internal power switch. If the VP voltage reaches a level higher than the UVLO
threshold plus UVLO hysteresis (V
re-enabled. See parameters 1.3.14 and 1.3.15 in section 1.3 for the UVLO threshold and hysteresis.
4.2
If the LED string becomes open or the FB pin is shorted to ground, the ZLED7015 would normally continually
boost the output voltage to potentially damaging levels. To prevent this, the ZLED7015 includes an integrated
over-voltage protection (OVP) mechanism. If the output voltage reaches the ZLED7015’s OVP threshold V
the protection circuitry is triggered and the device automatically turns off the internal switch, stopping the
boost function and protecting the device. Once the output voltage falls below the OVP threshold minus OVP
threshold hysteresis (V
The OVP threshold V
equation (5):
Where
Important: Care must be taken to select proper R
ZLED7015. See specification 1.3.16 in Table 1.3 for the over-voltage protection threshold voltage. Set V
3V higher than the normal operation output voltage.
Important: When setting V
Minimize noise coupling on the OVP pin, which could interfere with proper protection, by connecting a 10nF
ceramic capacitor to GND from OVP (C
4.3
The ZLED7015 features on-chip over-temperature protection. If its internal temperature exceeds the over-
temperature protection (OTP) threshold, T
internal power switch is disabled. Once the internal temperature has fallen below the OTP threshold minus the
OTP threshold hysteresis (T
Refer to Table 1.1 for the maximum package power dissipation specifications for the ZLED7015’s MSOP-10
package.
Data Sheet
December 20, 2011
ZLED7015
1.0MHz Boost Converter with Internal 35V Switch
V
V
OVP
OVP_TH
Operating Conditions
Under-Voltage Lockout
Over-Voltage Threshold and Open-Circuit Protection
Over-Temperature Protection
V
= Over-voltage protection threshold
OVP
= Internal over-voltage threshold reference voltage (see Table 1.3, parameter 1.3.16)

V
© 2011 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
_
TH
OVP
OVP_TH

for the ZLED7015 is selectable via the R1 and R2 resistor values determined by
(
OVP
R
OTP
-V
1
R

, care must be taken to ensure V
OVP_TH_HYS
2
- T
R
2
OTP_HYS
)
UVLO
OVP
), the device will enter soft-start mode.
+V
), the ZLED7015 enters the soft-start mode (see section 2.1).
).
OTP
UVLO_HYS
, due to high power dissipation and improper heat sinking, the
) the UVLO turns off and the internal power switch is
1
and R
OUT
2
values to ensure proper functioning of the
cannot exceed 35V.
18 of 22
UVLO
(5)
, the
OVP
OVP
,