Switched capacitor voltage divider delivers 10A

Dialog Semiconductor has announced a 10A switched-capacitor voltage divide-by-two, that operates at up to 98% efficiency, hitting or exceeding 95% at 10A.

Dialog DA9313

Called DA9313, it can deliver over 50W from less than in less than 10mm2 of board area.

Applications are expected when systems are powered from two Li-ion cells connected in series, such as notebook PCs, digital cameras and portable Bluetooth speakers.

Another use is constant current charging. “For smartphone direct charging applications, it can be used as a companion to the main charger IC,” said the firm. “During the constant-current charging phase, the DA9313 by-passes the main charger and delivers 6A to the battery without exceeding thermal design requirements. With 9V from a travel adaptor, a 3A USB Type-C cable can be used instead of a more costly 5A electronically-marked Type-C cable.”

Dialog DA9313 master slaveIf 100W is required, two can be operated in a master-slave configuration – with 70μA typical total quiescent current.

Although the output is unregulated, low-impedance internal switches keep the output close to Vin/2, drooping only a couple of hundred millivolts at full load.

Dialog DA9313 effThe chip is internally clocked at 6MHz and requires, for example, flying capacitors of ≥18µF at 5V 8Arms.

Internally there are two interleaved channels, cutting current noise at the input.

Dialog DA9313 eff fixed fOperation can be fixed frequency, or variable frequency (see curves), and can move between continuous conduction mode (CCM) at high load and discontinuous conduction mode (DCM) at lower vequency.

Stand-alone operation is possible, even in master-slave, as is control via I2C, or control via a user push-button.

Dialog DA9313 cctCapacitors

Close reading of the data sheet is required to determine exactly what capacitors go where.

Below is a (possibly none-to-accurate) transcription of the recommended capacitor table (Table 38) from the data sheet. Use it with the diagram to the left.

capacitor
Cxxx
value size dielectric tolerance rating Murata part
flying
FLY
4x
47µF
0603
(0805)
X5R±15% ±20% 6.3V GRM188R603476ME15
(GRM219R603476ME44# )
by-pass
O_PVC
IN_PVC
2x
4.7µF
0402 X5R±15% ±20% 10V GRM155R61A475MEAA
bootstrap
BS_PVC
2x
10nF
0402
(0201)
X7R±15% ±10% 16V
(10V)
GRM15XR71C103KA86#
(GRM033R71A103KA01#)
by-pass
O_VCORE
1x
2.2µF
0402 X5R±15% ±20% 6.3V GRM155R60J225ME95
decoupling
IN_PVC
2x
4.7µF
0402 X5R±15% ±20% 16V GRM155R61C475ME15

“#” indicates a package specification code
Not guaranteed accurate


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