L6731DTR STMicroelectronics, L6731DTR Datasheet - Page 3

• Manufacturer Part Number: L6731DTR
• Description: IC CTRLR ADJ STPDN SYNC 16-TSSOP
• Manufacturer: STMicroelectronics

Specifications of L6731DTR

• Applications: Controller, DDR
• Voltage - Input: 1.8 ~ 14 V
• Number Of Outputs: 1
• Voltage - Output: Adjustable down to 0.6V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 16-TSSOP Exposed Pad, 16-eTSSOP, 16-HTSSOP
• Output Voltage: 0.6 V to 18 V
• Input Voltage: 1.8 V to 14 V
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 497-6112-2

L6731D
1
Summary description
The controller is an integrated circuit realized in BCD5 (BiCMOS-DMOS, version 5)
fabrication that provides complete control logic and protection for high performance
step-down DC-DC and niPoL converters.
It is designed to drive N-channel MOSFETs in a synchronous rectified buck topology. The
output voltage of the converter can be precisely regulated down to 600 mV with a maximum
tolerance of ±0.8 %. If an external reference is used, it will be transferred divided by 2 to the
N.I. input of the error-amplifier, in accordance to the DDR memory specifications.
An internal resistor divider and a voltage buffer allow to achieve an accuracy of 1 % on both
Vtt and Vttref. It's possible to provide an external reference from 0V to 2.5 V in order to meet
the specification for DDRI and DDRII. The input voltage can range from 1.8 V to 14 V, while
the supply voltage can range from 4.5 V to 14 V. High peak current gate drivers provide for
fast switching to the external power section, and the output current can be in excess of 20 A.
The PWM duty cycle can range from 0 % to 100 % with a minimum on-time (T
than 100 ns making possible conversions with very low duty cycle at high switching
frequency. The device provides voltage-mode control that includes a selectable frequency
oscillator (250 kHz or 500 kHz).
The error amplifier features a 10 MHz gain-bandwidth-product and 5 V/µs slew-rate that
permits to realize high converter bandwidth for fast transient response. The device monitors
the current by using the R
the need for a current sensing resistor and guaranteeing an effective over-current-protection
in all the application conditions.
When necessary, two different current limit protections can be externally set through two
external resistors. During the soft-start phase a constant current protection is provided while
after the soft-start the device enters in hiccup mode in case of over-current. The converter
can always sink current. Other features are power good, not latched over-voltage-protection,
feed-back disconnection and thermal shutdown. The HTSSOP16 package allows the
realization of really compact DC/DC converters.
DS(on)
of both the high-side and low-side MOSFET(s), eliminating
Summary description
ON, MIN
) lower
3/23