ZXLD1374EST20TC Diodes Zetex, ZXLD1374EST20TC Datasheet - Page 26

• Manufacturer Part Number: ZXLD1374EST20TC
• Description: IC LED DVR BUCK BOOST 20TSSOP
• Manufacturer: Diodes Zetex
• Series: -r

Specifications of ZXLD1374EST20TC

• Constant Current: -
• Constant Voltage: -
• Topology: Low Side, PWM, Step-Down (Buck), Step-Up (Boost)
• Number Of Outputs: 1
• Internal Driver: Yes
• Type - Primary: Automotive, General Purpose
• Type - Secondary: High Brightness LED (HBLED)
• Frequency: 300kHz ~ 1MHz
• Voltage - Supply: 6.3 V ~ 60 V
• Voltage - Output: 60V
• Mounting Type: Surface Mount
• Package / Case: 20-TSSOP (0.173", 4.40mm Width) Exposed Pad
• Operating Temperature: -40°C ~ 125°C
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: ZXLD1374EST20TCDITR

ZXLD1374
Document number: DS35032 Rev. 2 - 2
Applications Information
The PWM pin is designed to be driven by both 3.3V and 5V logic levels. It can be driven also by an open drain/collector
transistor. In this case the designer can either use the internal pull-up network or an external pull-up network in order to
speed-up PWM transitions, as shown in the Boost/ Buck-boost section.
LED current can be adjusted digitally, by applying a low frequency PWM logic signal to the PWM pin to turn the controller on
and off. This will produce an average output current proportional to the duty cycle of the control signal. During PWM
operation, the device remains powered up and only the output switch is gated by the control signal.
The PWM signal can achieve very high LED current resolution. In fact, dimming down from 100% to 0, a minimum pulse
width of 5us can be achieved resulting in very high accuracy. While the maximum recommended pulse is for the PWM
signal is10ms.
Figure 45. PWM Dimming Minimum and Maximum Pulse
Figure 43. PWM Dimming from Open Collector Switch
(Continued)
Figure 44. PWM Dimming from MCU
60V HIGH ACCURACY 1.5A BUCK/BOOST/BUCK-BOOST
www.diodes.com
26 of 37
LED DRIVER CONVERTER WITH AEC-Q100
Diodes Incorporated
A Product Line of
© Diodes Incorporated
ZXLD1374
March 2011